Stem Cells for Wound Healing

ABSTRACT

The present invention provides a method for treating wounds by applying cells as described in this application. In one aspect the method provides treatment for cutaneous wounds. In general embodiments the cells are delivered to the wound without being attached to a functionalized substrate in the delivery vehicle.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has beensubmitted electronically in ASCII format and is hereby incorporated byreference in its entirety. Said ASCII copy, created on Feb. 12, 2021, isnamed ATY-0029US_SL.txt and is 6,609 bytes in size.

FIELD OF THE INVENTION

The present invention provides a method for treating wounds by applyingcells as described in this application. In one aspect the methodprovides treatment for cutaneous wounds. In general embodiments thecells are delivered to the wound without being attached to afunctionalized substrate in the delivery vehicle.

BACKGROUND OF THE INVENTION

The skin is the body's first line of defense from injury andmicroorganisms and plays an important role in the physical function.Traumatic injuries, burns and chronic ulcers may cause severe damage ofthe skin, which affects the primary immune function of the skin barrierand then may be accompanied with systemic risk.

Optimum healing of a cutaneous wound requires the processes ofinflammation, re-epithelialization, granulation tissue formation,angiogenesis, wound contraction and extracellular matrix (ECM)reconstruction, which contribute to skin tissue regeneration aftertraumatic injury.

Wound healing is an intricate process in which the skin tissue repairsitself after injury. In normal skin, the epidermis (surface layer) anddermis (deeper layer) form a protective barrier against the externalenvironment. When the barrier is broken, an orchestrated cascade ofbiochemical events is quickly set into motion to repair the damage. Thisprocess is divided into predictable phases: blood clotting (hemostasis),inflammation, the growth of new tissue (proliferation), and theremodeling of tissue (maturation). Sometimes blood clotting isconsidered to be part of the inflammation stage instead of its ownstage.

-   -   Hemostasis (blood clotting): Within the first few minutes of        injury, platelets in the blood begin to stick to the injured        site. This activates the platelets, causing a few things to        happen. They change into an amorphous shape, more suitable for        clotting, and they release chemical signals to promote clotting.        This results in the activation of fibrin, which forms a mesh and        acts as “glue” to bind platelets to each other. This makes a        clot that serves to plug the break in the blood vessel,        slowing/preventing further bleeding.    -   Inflammation: During this phase, damaged and dead cells are        cleared out, along with bacteria and other pathogens or debris.        This happens through the process of phagocytosis, where white        blood cells “eat” debris by engulfing it. Platelet-derived        growth factors are released into the wound that cause the        migration and division of cells during the proliferative phase.    -   Proliferation (growth of new tissue): In this phase,        (lymph)angiogenesis, collagen deposition, granulation tissue        formation, epithelialization, and wound contraction occur. In        angiogenesis, vascular endothelial cells form new blood vessels,        while lymphatic endothelial cells contribute to the formation of        new lymphatic vessels. In fibroplasias and granulation tissue        formation, fibroblasts grow and form a new, provisional        extracellular matrix (ECM) by excreting collagen and        fibronectin. Concurrently, restoration of the epidermis occurs,        in which epithelial cells proliferate and “crawl” atop the wound        bed, providing cover for the new tissue. In wound contraction,        myofibroblasts decrease the size of the wound by gripping the        wound edges and contracting using a mechanism that resembles        that in smooth muscle cells. When the cells' roles are close to        complete, unneeded cells undergo apoptosis.    -   Maturation (remodeling): During maturation and remodeling,        collagen is realigned along tension lines, and cells that are no        longer needed are removed by programmed cell death, or        apoptosis.

The wound healing process is not only complex but also fragile, and itis susceptible to interruption or failure leading to the formation ofnon-healing chronic wounds. Factors that contribute to non-healingchronic wounds are diabetes, venous or arterial disease, infection, andmetabolic deficiencies of old age.

Wounds can result from a variety of causes, including for exampletrauma, disease, action of micro-organisms and exposure to foreignmaterials. Wound healing it not only important to achieve wound closure,but is also important to restore tissue functionality and to provide abarrier function against infection. Delayed wound healing is asignificant contributor to morbidity in subjects. In some situations,the wound healing process is dysfunctional, leading to the developmentof chronic wounds. Chronic wounds have major impacts on the physical andmental health, productivity, morbidity, mortality and cost of care foraffected individuals.

Chronic wounds are defined as wounds that fail to heal after 3 months.Venous stasis ulcers, diabetic ulcers, pressure ulcers, and ischemiculcers are the most common chronic wounds. Many of the dressing optionsthat attempt to heal venous stasis ulcers are a variation on the classicpaste compression bandage, Unna's boot. These wounds can sometimes havelarge amounts of exudates that require frequent debridement. Alginates,foams and other absorptive can be used in this situation. Becausechronic wounds heal by slightly different mechanisms than those of acutewounds, experimentation with growth factors is being investigated.Regranex® and Procuren® (Curative Health Services, Inc., Hauppauge,N.Y.) are the only medications approved by the U.S. Food and DrugAdministration (FDA).

Wound care encourages and speeds wound healing via cleaning andprotection from reinjury or infection. Depending on each patient'sneeds, it can range from the simplest first aid to entire nursingspecialties such as wound, ostomy, and continence nursing and burncenter care.

Each year, over 1.5 million skin wounds are due to burns and over 1million skin wounds are due to skin cancer. Each year, skin woundsresult in about 75,000 inpatient cases and 12,000 deaths, and in 2005,about $3.3 billion dollars were spent on wound care.

In the body, skin wound healing involves fibroblast secretion of aprovisional matrix, a process that usually begins 7 days post-injury.However, the currently available tissue engineered skin substitutes aredecellularized human skin, such as Alloderm®, which are used for humansin cases of chronic skin wounds (e.g., due to diabetes, vasculitis,malnutrition, infection), acute skin wounds (e.g., burns, skin cancer),skin malformation, etc. Such decellularized skin substitutes lackadnexal structures (e.g., sebaceous glands, hair follicles,melanocytes), a rete ridge pattern at the epidermal-dermal junction, andother vital living components that promote wound healing. Furthermore,high risk of infection remains in heterologous transplantation of thecurrently available skin substitutes.

Since the regeneration of both dermal and epidermal skin layers arecritical for successful wound healing with limited scar formation andinfection, new models are needed that are “true” skin substitutes.

The most commonly used conventional modality to assist in wound healinginvolves the use of wound dressings. A variety of different types ofdressings are used to assist with wound healing. Some treatments havealso utilized the provision of minerals and vitamins to assist withwound healing. However, these types of treatment modalities have metwith little success. As such, current clinical approached used topromote wound healing include protection of the wound bed frommechanical trauma, control of surface microbial burden throughantibiotics, antiseptics and other antimicrobial compounds, and the useof some types of growth factors. However, these approaches all have avariety of disadvantages.

The healing of wounds is an example where the delivery of cells hastherapeutic potential. Despite advances in the understanding of theprinciples underlying the wound healing process, the therapeutic optionsfor wound treatment still remain limited. Cell delivery strategiesprovide a potential therapeutic avenue.

While the delivery of cells has therapeutic potential, the use of celldelivery still remains limited for a number of reasons. For example,considerations such as how cells should be delivered, substrateselection, attachment of cells, efficiency of cell transfer and/or theability of cells to retain their therapeutic properties are important totherapeutic outcome.

Researchers have used stem cells from different sources to treattraumatic skin injury, to accelerate the regeneration and reconstructionof the skin defects (Yaojiong et al., Stem Cells, 25(10): 2648-59,2007). However, there are still problems with stem cell therapies, suchas limited sources of stem cells. Accordingly, there is a continuingneed to identify new cells and/or means for delivery of cells, fortherapeutic purposes.

Despite these advances in the art, a need exists in the art for new andbetter methods and devices for restoring the natural process of woundhealing at a lesion, the repair of which requires tissue remodeling andrestoration.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a method for treating certain wounds byapplying to those wounds certain cells as described herein for healingthe wound.

Routes of delivery include, but are not limited to, topicaladministration forms. Examples of forms of topical administrationinclude delivery by way of a gel, an ointment, a cream, a lotion, afoam, an emulsion, a suspension, a spray, an aerosol, a solution, aliquid, a powder, a semi-solid, a gel, a jelly; a solid, a paste, atincture, a liniment, a degradable carrier, a pharmaceuticallyacceptable carrier, a fluid, a reservoir, a liquid, a gel, an implant,such as a PVA-loaded sponge, collagen gel solution, membranepreparation, such as placental membranes, amniotic membranes, collagensponge, fibrin or other protein glue, in fluid communication suspensionin a pharmaceutically acceptable carrier, for example, saline, sugars,for example, dextrose, isotonic aqueous diluent solution, powder, a skinsubstitute, such as a protein, e.g., fibrin, or membrane preparation,decellularized tissue preparations, for example, decellularized skinpreparations, a scaffold, including hydrogel, Matrigel, spongastan,fibronectin, PLGA, collagen gel, fibrin spray, or other protein spray ormembrane spray.

Administration may also be by means of a patch, bandage, gauze, ordressing, wherein the bandage, patch, gauze, or dressing does notcontain a functionalized substrate to which the cells are attached andfrom which they migrate to the wound, such as, chemical modificationwith an alkyl group, such as, an alkylamine group. Other forms oftopical delivery are contemplated.

Delivery may also be intradermal or subcutaneous with any of the formsmentioned above with respect to topical delivery.

The cells may be delivered by local injection to the wound in any of theappropriate carriers, such as those mentioned above, with respect totopical administration.

The cells may be implanted in a wound with any of the above deliveryvehicles as appropriate, for example, in a PVA-loaded sponge.

In certain embodiments the cells are not delivered in a bandage, gauze,patch, or dressing. In more specific embodiments the cells are notdelivered in any of these vehicles wherein the vehicles comprise afunctionalized substrate. In more specific embodiments the vehicles donot include a functionalized substrate that is a chemical modification,such as with an alkyl group, such as an alkylamine group.

However, the cells may be delivered by means of functionalizedsubstrates that do not include chemical modifications with alkyl groups.Thus, the cells could be delivered by way of substrates functionalizedwith protein or other biological material that is derived from tissuesor mimic those found in tissues such as membrane preparations,including, but not limited to, amniotic membrane.

In specific excluded embodiments, the cells are not delivered by meansof a device (such as bandage, gauze, dressing, or patch) that ischemically modified with an alkyl group and, particularly, an alkylaminegroup.

In one aspect, the cells are delivered to the wound but not in acell-laden patch, bandage, or dressing. In a specific embodiment thecells are not attached to a functionalized substrate.

The cells described herein may be administered to the wound in apharmaceutically acceptable carrier. Pharmaceutically-acceptablecarriers include, but are not limited to, water, glucose, glycerol,saline, ethanol, liquid oil, such as palmitates, polyethylene glycol,tween, and SDS, among others.

In certain embodiments, the pharmaceutical composition is suitable fordelivery to a subject by one or more of intravenous administration, byaerosolized administration, by parenteral administration, by implant, bysubcutaneous injection, intraarticularly, rectally, intranasally,intraocularly, vaginally, or transdermally.

In certain embodiments, the pharmaceutical composition comprises othercompounds that enhance, stabilize or maintain the activity of the cellsfor delivery and/or their delivery or transfer.

In certain embodiments, it may be desirable to administer thepharmaceutical composition parenterally (such as directly into the jointspace) or intraperitoneally. For example, solutions or suspensions canbe prepared in water suitably mixed with a surfactant such ashydroxy-propylcellulose. Dispersions can also be prepared in glycerol,liquid polyethylene glycols and mixtures thereof in oils.

In certain embodiments, it may be desirable to administer thecomposition by injection. Forms suitable for injectable use includesterile aqueous solutions or dispersions and sterile powders for theextemporaneous preparation of sterile injectable solutions ordispersions. A carrier can be a solvent or dispersion medium containing,for example, water, ethanol, polyol (e.g., glycerol, propylene glycoland liquid polyethylene glycol), suitable mixtures thereof, andvegetable oils.

In certain embodiments, it may be desirable to administer thecomposition intravenously. Compositions containing the compositiondescribed herein suitable for intravenous administration may beformulated by a skilled person.

In certain embodiments the composition may be administered by injection,e.g., as a cell suspension, in a foam or paste, i.e., by 3D supportconsisting of polymers or other molecules, meshes, or micro-carriers.

In one aspect, the present invention provides a method for treating awound to the skin, which comprises administering to the skin wound acomposition comprising stem cells. The wound to the skin can be limitedor extensive. It can be confined to the epidermis or can also involvethe dermis, fatty layer, muscle, and even bone. Thus, the wound canextend to cutaneous and subcutaneous tissues.

The wound may be selected from the group consisting of lacerations,scrapes, burns, incisions, punctures, wounds caused by a projectile andepidermal wounds, skin wound, chronic wound, acute wound, externalwound, internal wound, congenital wound, ulcer, pressure ulcer, diabeticulcer, tunnel wound, wound caused during or as an adjunct to a surgicalprocedure, venous skin ulcer, and avascular necrosis.

In one embodiment the wounds are of a class that arise because ofinsufficient blood and/or lymphatic circulation. Within this class,species include, in particular, chronic wounds that result from thisinsufficient circulation, such as, diabetic ulcers, venous skin ulcers,and avascular necrosis. In particular cutaneous wounds may be treated bythe methods of the invention. It is understood, however, that thesecutaneous wounds, particularly when chronic, can affect the subcutaneouslayers and may actually expose deeper muscle and even bone tissue. Thiscan be the case with diabetic foot ulcers, venous leg ulcers and burns.

The term “wound” includes, for example, an injury to a tissue, includingopen wounds, delayed or difficult to heal wounds, and chronic wounds.Examples of wounds may include both open and closed wounds. The term“wound” also includes, for example, injuries to the skin andsubcutaneous tissue and injuries initiated in different ways and withvarying characteristics.

In certain embodiments, the wound comprises an external wound. Incertain embodiments, the wound comprises an open wound. In certainembodiments, the wound comprises a chronic wound. In certainembodiments, the wound comprises a chronic wound or an ulcer.

For external wounds, typically these wounds are classified into one offour grades depending on the depth of the wound: i) Grade I woundslimited to the epithelium; ii) Grade II wounds extending into thedermis; iii) Grade III wounds extending into the subcutaneous tissue;and iv) Grade IV (or full-thickness wounds) wounds wherein bones areexposed.

The invention is directed to methods of promoting cutaneous woundhealing, including, administering to a patient an effective amount ofstem cells, thereby resulting in at least one of accelerated woundclosure, rapid re-epithelialization, improved (lymph)angiogenesis andimproved tissue remodeling, relative to untreated controls.

Positive results in wound healing include, but are not limited to,enhanced epithelialization, granulation tissue formation andangiogenesis, accelerated wound closure, deposition of granulationtissue, increased wound bursting strength with increased collagencontent, increased wound tensile strength, reduced scarring, and reducedwound size.

Wounds include cutaneous wounds. They also include wounds that reach alllayers of the dermis, including, the subcutaneous and fat layers, i.e.,the underlying tissues as well. The invention applies to chronic wounds,wounds that result from obesity or diabetes, non-healing diabeticwounds, diabetic wounds in general, diabetic foot ulcers, burns,neuropathic foot ulcers, diabetic neuropathic ulcers, and chroniccutaneous ulcers. Wounds may result in the cutaneous and subcutaneoustissues by underlying causes, such as, lack of sufficient bloodcirculation or lymphatic circulation. Methods of the present inventionand compositions of the present invention, thus, promotere-epithelialization, i.e., wound closure whether full or partial.

In accordance with a further aspect of the present invention, there isprovided a method of promoting wound healing in a subject. The methodcomprises administering to the subject stem cells in an amount effectiveto promote wound healing in the subject. In one embodiment the subjectis human. However, the invention includes veterinary subjects (e.g.,dogs, cats, pigs, horses, etc.).

There are three phases of normal wound healing including, bleeding andcoagulation, acute inflammation, cell migration, proliferation,differentiation, angiogenesis, re-epithelialization, and synthesis andremodeling of extracellular matrix. All of these events occur in threeoverlapping phases, specifically, inflammatory, proliferative, andremodeling. The cells in the present application can be used in one ormore of these phases. They need not be used, but may be used, in allthree of these phases.

Chronic wounds are those that fail to progress through the three normalstages of healing. This results in tissue injury that is not repairedwithin the typical time period. These may result from various underlyingdisorders that include, but are not limited to, diabetes, pressure,vascular insufficiency, burns, and vasculitis (Borue, et al.; Am JPathol (2004) 165:1767-1772). The cells in the present application canbe used in one or more of these stages.

The stem cells are administered to the animal in an amount effective topromote wound healing in the animal. The animal may be a mammal, and themammal may be a primate, including human and non-human primates. Ingeneral, the stem cells are administered in an amount of from about1×10⁵ cells/kg to about 1×10⁷ cells/kg, preferably from about 1×10⁶cells/kg to about 5×10⁶ cells/kg. In a specific embodiment 2-4×10⁷cells/kg are administered. The exact amount of stem cells to beadministered is dependent upon a variety of factors, including the age,weight, and sex of the patient, and the extent and severity of the woundbeing treated.

The stem cells may be administered in conjunction with an acceptablepharmaceutical carrier. The stem cells may be administered systemically.The stem cells may be administered directly to a wound, a fluid orreservoir containing the stem cells such as PBS, buffered salts, cellmedia, PlasmaLyte.

In some embodiments the cells are delivered with additional factors.These include, but are not limited to, one or more of antiflammatory andantimicrobial factors, including defensins, N-Gal, IL-1RA, angiogenicfactors, such as, VEGF, bFGF, PDGF, epithelial cell stimulatoryproteins, including KGF and EGF and antiscarring proteins TGFβ3, IFNα2,and HGF.

The cells to which the invention is directed may express pluripotencymarkers, such as oct4. They may also express markers associated withextended replicative capacity, such as telomerase. Other characteristicsof pluripotency can include the ability to differentiate into cell typesof more than one germ layer, such as two or three of ectodermal,endodermal, and mesodermal embryonic germ layers. Such cells may or maynot be immortalized or transformed in culture. The cells may be highlyexpanded without being transformed and also maintain a normal karyotype.For example, in one embodiment, the non-embryonic stem, non-germ cellsmay have undergone at least 10-40 cell doublings in culture, such as 50,60, or more, wherein the cells are not transformed and have a normalkaryotype. The cells may differentiate into at least one cell type ofeach of two of the endodermal, ectodermal, and mesodermal embryoniclineages and may include differentiation into all three. Further, thecells may not be tumorigenic, such as, not producing teratomas. If cellsare transformed or tumorigenic, and it is desirable to use them forinfusion, such cells may be disabled so they cannot form tumors in vivo,as by treatment that prevents cell proliferation into tumors. Suchtreatments are well known in the art.

Cells include, but are not limited to, the following numberedembodiments:

1. Isolated expanded non-embryonic stem, non-germ cells, the cellshaving undergone at least 10-40 cell doublings in culture, wherein thecells express oct4, are not transformed, and have a normal karyotype.

2. The non-embryonic stem, non-germ cells of 1 above that furtherexpress one or more of telomerase, rex-1, rox-1, or sox-2.

3. The non-embryonic stem, non-germ cells of 1 above that candifferentiate into at least one cell type of at least two of theendodermal, ectodermal, and mesodermal embryonic lineages.

4. The non-embryonic stem, non-germ cells of 3 above that furtherexpress one or more of telomerase, rex-1, rox-1, or sox-2.

5. The non-embryonic stem, non-germ cells of 3 above that candifferentiate into at least one cell type of each of the endodermal,ectodermal, and mesodermal embryonic lineages.

6. The non-embryonic stem, non-germ cells of 5 above that furtherexpress one or more of telomerase, rex-1, rox-1, or sox-2.

7. Isolated expanded non-embryonic stem, non-germ cells that areobtained by culture of non-embryonic, non-germ tissue, the cells havingundergone at least 40 cell doublings in culture, wherein the cells arenot transformed and have a normal karyotype.

8. The non-embryonic stem, non-germ cells of 7 above that express one ormore of oct4, telomerase, rex-1, rox-1, or sox-2.

9. The non-embryonic stem, non-germ cells of 7 above that candifferentiate into at least one cell type of at least two of theendodermal, ectodermal, and mesodermal embryonic lineages.

10. The non-embryonic stem, non-germ cells of 9 above that express oneor more of oct4, telomerase, rex-1, rox-1, or sox-2.

11. The non-embryonic stem, non-germ cells of 9 above that candifferentiate into at least one cell type of each of the endodermal,ectodermal, and mesodermal embryonic lineages.

12. The non-embryonic stem, non-germ cells of 11 above that express oneor more of oct4, telomerase, rex-1, rox-1, or sox-2.

13. Isolated expanded non-embryonic stem, non-germ cells, the cellshaving undergone at least 10-40 cell doublings in culture, wherein thecells express telomerase, are not transformed, and have a normalkaryotype.

14. The non-embryonic stem, non-germ cells of 13 above that furtherexpress one or more of oct4, rex-1, rox-1, or sox-2.

15. The non-embryonic stem, non-germ cells of 13 above that candifferentiate into at least one cell type of at least two of theendodermal, ectodermal, and mesodermal embryonic lineages.

16. The non-embryonic stem, non-germ cells of 15 above that furtherexpress one or more of oct4, rex-1, rox-1, or sox-2.

17. The non-embryonic stem, non-germ cells of 15 above that candifferentiate into at least one cell type of each of the endodermal,ectodermal, and mesodermal embryonic lineages.

18. The non-embryonic stem, non-germ cells of 17 above that furtherexpress one or more of oct4, rex-1, rox-1, or sox-2.

19. Isolated expanded non-embryonic stem, non-germ cells that candifferentiate into at least one cell type of at least two of theendodermal, ectodermal, and mesodermal embryonic lineages, said cellshaving undergone at least 10-40 cell doublings in culture.

20. The non-embryonic stem, non-germ cells of 19 above that express oneor more of oct4, telomerase, rex-1, rox-1, or sox-2.

21. The non-embryonic stem, non-germ cells of 19 above that candifferentiate into at least one cell type of each of the endodermal,ectodermal, and mesodermal embryonic lineages.

22. The non-embryonic stem, non-germ cells of 21 above that express oneor more of oct4, telomerase, rex-1, rox-1, or sox-2.

The cells described above can be prepared from any desirable tissuesource, including, but not limited to, bone marrow, umbilical cordblood, umbilical cord matrix, peripheral blood, placenta, placentalblood, muscle, brain, kidney, and other solid organs. They can also bederived from excreted fluids, such as urine and menstrual blood.

In one embodiment, the cells are derived from human tissue.

In specific embodiments the wound contains epithelial damage.

In certain embodiments the cells themselves need not be delivered. Thetherapeutic effects may be achieved by factors that are secreted by thecells. For example, when the cells are cultured the beneficial factorsmay be secreted into the cell culture medium. Therefore, the medium,itself, may be used in the various embodiments disclosed in theapplication. Alternatively, extracts of the conditioned medium may beused, the extracts containing the beneficial factors by which the cellsprovide a therapeutic result in wound healing as described in thisapplication. Thus wherever cells may be delivered, the conditionedmedium or extracts thereof may be substituted or added.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A-1M: FIGS. 1A and B; Diagram representing expression of general(right) and lymphatic-specific (left) endothelial cell (EC) markers,shown as % versus universal mouse RNA in undifferentiated mMAPCs (A) orversus universal human RNA in undifferentiated hMAPCs (d0, white), at 14(d14, gray) and 21 (d21, black) days of differentiation. Data representmean±SEM of 5-6 independent differentiations. *P<0.05 versus d0 byKruskal-Wallis test with Dunn's post-hoc test. FIG. 1C; FACS histogram(representative of n=3) showing LYVE1 protein expression (full line)versus isotype control (dashed line) in mMAPCs at d14. APC:allophycocyanine. FIG. 1D; Diagram representing LYVE1 expression, shownas fold-increase versus undifferentiated hMAPCs (d0, white), or at d9 inthe presence of VEGF-A (light gray), VEGF-C (dark gray) or a combination(black). Data represent mean±SEM of n=3. *P<0.05 versus d0 by 1-wayANOVA with Tuckey's post-hoc test. FIGS. 1E-G; Representative images ofhuman lymphatic EC (hLEC) spheroids exposed to LEC media (E; ‘L’) orconditioned media from mMAPCs (‘mCM’; F), and correspondingquantification (G; data represent mean±SEM of n=4; *P<0.05 versus 1′ byMann-Whitney-U test). FIG. 1H; Diagram representing the effect of mouse(‘mCM’) or human (‘hCM’) MAPC-CM on LEC proliferation, expressed as %versus LEC media. Data represent mean±SEM of n=3-6. *P<0.05 versus TEC′by Mann-Whitney-U test. FIGS. 1I-M; Representative images of LECsmigrated across the membrane of a transwell (revealed by Wright-Giemsastaining) in the presence of non-conditioned mMAPC media (NCM; J),mMAPC-CM (K), non-conditioned hMAPC media (NCM; L) or hMAPC-CM (M) andthe corresponding quantification (I; data represent mean±SEM of n=4;*P<0.05 versus corresponding NCM condition by Mann-Whitney-U test).Scale bars: 50 μm (E,F); 100 μm (J-M).

FIG. 2A-2P: FIG. 2A; Wound width in mice treated with PBS (open circles)or mMAPCs (filled circles). Data represent mean±SEM. n=5; *P<0.05 versusPBS by repeated measures ANOVA and Fisher post-hoc test. FIG. 2B; Mergedbrightfield/fluorescent image of the wound (indicated by arrows) area ofa mouse transplanted with eGFP⁺ mMAPCs 4 d earlier. Note the mMAPCs areclose to blood vessels (indicated by arrowheads) leading towards thewound bed. FIGS. 2C and D; Representative pictures of CD31-stained(brown) cross-sections of 10 d-old wounds from mice treated with PBS (C)or mMAPCs (D). FIGS. 2E-G; Representative pictures of LYVE1-stained(red) cross-sections of 10 d-old wounds from mice treated with PBS (E)or mMAPCs (F), and corresponding quantification (G; data representmean±SEM. *P<0.05 versus PBS by Mann-Whitney-U test; n=4-5). FIG. 2H;Confocal image of a cross-section of a mouse transplanted with eGFP⁺mMAPCs 10 d earlier revealing occasional co-localization (arrowhead) ofeGFP with LYVE1 (red). FIGS. 2I and J; Representative images ofcross-sections of wounds treated with PBS (I) or hMAPCs (J) 5 d earlier,stained for pancytokeratin (PCK; brown; arrowheads indicate woundborders, horizontal lines indicate distance covered by the epidermis).FIGS. 2K and L; Representative images of CD31-stained (brown)cross-sections of wounds treated with PBS (K) or hMAPCs (L) 10 dearlier. FIGS. 2M-O; Representative pictures of LYVE1-stained (red)cross-sections of 10 d-old wounds from mice treated with PBS (M) orhMAPCs (N), and corresponding quantification (O; data representmean±SEM. *P<0.05 versus PBS by unpaired Student's t-test; n=6-8). FIG.2P; Image of a wound cross-section of a mouse transplanted with hMAPCs10 d earlier revealing occasional co-localization (arrowheads) ofhVimentin (green) with LYVE1 (red). Hematoxylin and DAPI were used toreveal nuclei in C,D,I-L and E,F,M,N, respectively. Scale bars: 10 μm(H,P); 100 μm (E,F); 150 μm (K,L); 400 μm (C,D,I,J,M,N); 2 mm (B).

FIG. 3A-3D: FIG. 3A; Image displaying the skin flap model. R1/R2indicate the areas from which images in panel B-D are shown. Arrows/A′indicate injection spots of fluorescently-labeled dextran forlymphangiography or MAPCs/PBS, respectively, and arrowheads show thearea through which blood supply to the skin flap is preserved. FIGS.3B-D; Representative merged pictures of brightfield/fluorescent images15 min after injection of dextran (FITC-labeled in B,D orRhodamin-B-labeled in C) of regions R1 (left; and enlarged image of thecorresponding inset (i; middle)) and R2 (right) of mice injected 2 wearlier with PBS (B), mMAPCs (C) or hMAPCs (D). Arrowheads indicatefilled afferent lymphatic vessels. LN: lymph node. Dashed lines in R1/R2delineate border of the opened skin or the flap border, respectively.Scale bars: 100 μm (B; i1, C; i2+R2, D; i3); 250 μm (B; R1+R2, C; R1, D;R1+R2); and 500 μm (A).

FIGS. 4A-4L: FIGS. 4A-D; Representative pictures of Flt4-stained (brown)skin wound cross-sections (around the location of dextran injection)from mice treated with PBS (A), mMAPCs (‘mM’; B) or hMAPCs (‘hM’; C),and corresponding quantification (D; data represent mean±SEM. *P<0.05versus PBS by Kruskal-Wallis with Dunn's post-hoc test; n=6). FIGS.4E-H; Representative pictures of skin wound cross-sections (around thelocation of dextran injection) from mice treated with PBS (E), mMAPCs(‘mM’; F) or hMAPCs (‘hM’; G) revealing functional (dextran-perfused)lymphatic vessels (green or red) in cell-treated mice, and correspondingquantification (H; data represent mean±SEM. *P<0.05 versus PBS byKruskal-Wallis with Dunn's post-hoc test; n=5-10). Inset (i1) in E showsthe corresponding region stained for Prox1 (red). Note the diffusefluorescence signal in E representing FITC-dextran that failed to betaken up by lymphatic vessels. FIG. 41; Merged brightfield/fluorescentimage of the wound area of a mouse transplanted with eGFP⁺ mMAPCs(injection spots indicated by arrowheads) 2 w earlier. FIG. 4J; Mergedgreen/red fluorescent images of the wound area of a mouse transplantedwith eGFP⁺ mMAPCs (arrow) 4 w earlier. Note the Rhodamin-dextran-filledlymphatic vessels (red; arrowheads) in the vicinity of the transplantedcells. FIG. 4K; Cross-section through the area around the wound,revealing transplanted eGFP⁺ mMAPCs adjacent to functional(Rhodamin-dextran-filled, red; lumen indicated by asterisks) lymphaticvessels. FIG. 4L; High power magnification of the wound areatransplanted with eGFP⁺ mMAPCs 2 w earlier revealing that occasionallythese cells become part of the endothelial lining (arrowheads) offunctional (Rhodamin-dextran-filled, in red) lymphatic vessels.Hematoxylin and DAPI were used to reveal nuclei in A-C, and E-G,K,respectively. Scale bars: 25 μm (L); 50 μm (E-G); 100 μm (A-C,J,K); 500μm (I).

FIG. 5A-5G: FIG. 5A; Merged brightfield/fluorescent image of the rightaxillary region of a mouse transplanted with an eGFP⁺ lymph node (LN;arrowhead) and treated with Matrigel® containing hMAPCs 16 w earlier.The area covered with solidified Matrigel® and the open skin border areindicated by a dashed and full white lines, respectively. FIG. 5B;Diagram representing the extent of edema in the right upper limb(determined by MRI and shown as right/left ratio in AU) in mice treatedwith Matrigel® containing PBS or hMAPCs 4 w or 16 w after LNtransplantation. *P<0.05 versus w4 by unpaired Student's t-test (n=4-9).FIGS. 5C and D; Representative T₂-weighted MR images of the antebrachialregions of mice treated with Matrigel® containing PBS (C) or hMAPCs (D),recorded 16 w after LN transplantation. Hyperintense areas (arrows)indicate accumulation of fluid due to edema. L: left; R: right. FIGS. 5Eand F; Merged brightfield/fluorescent image of the right axillary regionof a mouse transplanted with an eGFP⁺ LN (arrowhead) and treated withMatrigel® containing PBS (E) or hMAPCs (F) 16 w earlier. Inset (i1)zooms in on the boxed area in F. Note the significantly improveddrainage of the Rhodamin-labeled lectin (red) in hMAPC-treated micerecorded 15 min after injection (injection spot indicated by arrow). Theborder of the opened skin is indicated by white lines. FIG. 5G; Mergedbrightfield/fluorescent image zooming in on an eGFP⁺ LN (green)transplanted in a mouse treated with Matrigel® containing hMAPCs 16 wearlier, revealing drainage of the Rhodamin-labeled lectin (red) intothe LN. Arrowheads indicate afferent lymph vessel. Scale bars: 200 μm(G); 3 mm (A,E,F).

FIGS. 6 A-6N: FIGS. 6A-C; Brightfield images of the blood vessel networkleading up to the transplanted lymph node (LN) of mice treated withMatrigel® containing PBS (A) or hMAPCs (‘hM’; B) 16 w earlier, andcorresponding quantification (C; data represent mean±SEM. *P<0.05 versusPBS by Mann-Whitney-U test; n=6). FIG. 6D; Mergedbrightfield/fluorescent image of an eGFP⁺ LN transplanted in a mousetreated with Matrigel® containing hMAPCs 16 w earlier revealing that theLN is irrigated by numerous blood vessels. FIGS. 6E and F; Mergedbrightfield/fluorescent images zooming in on a DsRed+LN transplanted inmice treated with Matrigel® containing hMAPCs 8 w earlier revealingextensive branching of the LN vascular network. Inset (i1) correspondsto the boxed area in F. FIG. 6G; Merged IF image of a Prox1/eGFP-stainedsection in a mouse treated with Matrigel®+hMAPCs 16 w earlier revealingthat part of the branches are lymphatic (Prox1⁺, arrowheads). Inset (i2)corresponds to the boxed area in G. FIGS. 6H-J; LYVE1-stained (red)cross-sections of PBS (H) or hMAPC-treated (‘hM’; I) mice in the areaaround the sutures at 8 w after LN transplantation and correspondingquantification (J; data represent mean±SEM. *P<0.05 versus PBS byStudent's t-test; n=5-8). FIGS. 6K-M; Fluorescence images of the areaaround the transplanted eGFP⁺ LN (lined by a dashed line in K; adjacentsection stained for Prox1 in green is shown in L; Prox1/smooth muscleα-actin (αSMA in red, indicated by arrowheads; double staining in Mzooms in on the boxed area in K,L; and FIG. 6N represents the same areaon an adjacent cross-section stained for LYVE1 in red) revealingProx1⁺αSMA⁺LYVE1 draining lymphatic collector vessels in mice treated 16w earlier with Matrigel® containing hMAPCs. Asterisks in L-N indicatelymph (which artifactually fluoresces upon exposure to tyramide-basedamplification). White arrows in A,B,E-L indicate the sutures used to fixthe transplanted LN. Scale bars: 20 μm (M,N); 50 μm (G,K,L); 100 μm (D);150 μm (F; i1); 200 μm (E,H,I); 500 μm (F); 1 mm (A,B).

FIGS. 7A-7H: FIG. 7A; Diagram representing wound length (in mm) in micetreated with PBS (n=5: open circles) or mMAPCs (n=5; filled circles)until 10 d after wounding. Data represent mean±SEM. *P<0.05 versus PBSby repeated measures ANOVA with Fisher post-hoc test. FIGS. 7B and C;Representative brightfield pictures of linear wounds on the back of micetreated with PBS (B) or murine (m)MAPCs (C) 10 d after wounding. FIGS.7D and E; Representative pictures of cross-sections of 10 d-old woundsfrom mice treated with PBS (D) or mMAPCs (E) stained with H&E. Note thesignificantly smaller wound gap (the edges of which are indicated byarrowheads) in mMAPC-treated mice. FIG. 7F; Merged picture of red andgreen fluorescent image of a wound cross-section revealing noco-localization of CD45 (in green) with LYVE1 (in red). FIG. 7G; Mergedpicture of brightfield/fluorescent image of the wound bed 24 h afterseeding of eGFP-labeled hMAPCs revealing homogenous distribution ofeGFP+ hMAPCs across the wound area. FIG. 7H; Image of a vimentin-stained(green) wound cross-section of a mouse transplanted with hMAPCs 10 dearlier revealing persistence of large patches of hMAPCs homogenouslydistributed across the wound bed. The dermo-epidermal junction isindicated by a dashed line. DAPI was used as nuclear counterstain in H.Scale bars: 20 μm in F; 100 μm in H; 300 μm in D,E; 1 mm in G; and 2 mmin B,C.

FIGS. 8A-8I: FIGS. 8A-D; Representative pictures of cross-sections ofthe skin wound (around the location of transplantation indicated by ‘X’in FIG. 3A) from mice treated with PBS (A), mMAPCs (‘mM’; B) or hMAPCs(‘hM’; C) stained for CD31 (in brown), and corresponding quantification(D; data represent mean±SEM. *P<0.05 versus PBS by Kruskal-Wallis testwith Dunn's post-hoc test; n=5). FIGS. 8E-H; Representative pictures ofcross-sections of the skin wound (around the location of dextraninjection indicated by arrow in FIG. 3A) from mice treated with PBS (E),mMAPCs (‘mM’; F) or hMAPCs (‘hM’; G) stained for LYVE1 (red in E,G;green in F), and corresponding quantification (H; data representmean±SEM. *P<0.05 versus PBS by Kruskal-Wallis test with Dunn's post-hoctest; n=6).

FIG. 81; Merged picture of green (FITC-labeled dextran), red (Prox1) andfar-red (smooth muscle cell-α-actin; αSMA) fluorescent microscopicimages of the wound area (around the location of transplantationindicated by ‘X’ in FIG. 3A) of a mouse transplanted with hMAPCs 2 wearlier, revealing a functional αSMA-coated (arrowheads) Prox1⁺lymphatic (pre-)collector vessel in addition to two small functionalProx1⁺/αSMA lymphatic capillaries (lined by white dashed lines). Theautofluorescent muscle cells of the fascia are lined by a red dashedline. Scale bars: 10 μm in I; and 100 μm in A-C,E-G.

FIGS. 9A-9H: FIGS. 9A and B; T₂ maps corresponding to the T₂-weighted MRimages shown in FIG. 5C,D of the antebrachial regions of mice treatedwith Matrigel® containing PBS (A) or hMAPCs (B), recorded 16 w after LNtransplantation. L: left; R: right. FIG. 9C; Merged picture of green andred fluorescent microscopic images of the right axillary region of amouse transplanted with a DsRed⁺ LN and treated with Matrigel®containing hMAPCs 8 w earlier. Note the afferent lymphatic vessel filledwith FITC-labeled lectin (in green), indicated by arrowheads. FIGS. 9Dand E; Merged pictures of brightfield and green fluorescent images ofthe right axillary region of mice transplanted with an eGFP⁺ LN andtreated with Matrigel® containing PBS (D) or hMAPCs (E) 16 w earlier,revealing a more elaborate blood vessel network irrigating thetransplanted LN of hMAPC-treated mice. FIG. 9F; Merged picture of a redand green fluorescent image of a cross-section of the right axillaryregion of a mouse transplanted with an eGFP⁺ LN and treated with hMAPCs16 w earlier, revealing persisting vimentin-stained (in red) hMAPCssurrounding the transplanted LN. FIG. 9G; Merged picture of brightfieldand green fluorescent images of the right axillary region of a mousetransplanted with an eGFP⁺ LN and treated with Matrigel® containinghMAPCs 4 w earlier, revealing outward branching of the (lymph)vascularnetwork. FIG. 9H; Merged picture of an eGFP-stained cross-section of theright axillary region of a mouse transplanted with an eGFP⁺ LN andtreated with Matrigel® containing hMAPCs 16 w earlier, revealing outwardbranches of the (lymph)vascular network. Permanent sutures fixing thetransplanted LN are indicated by arrows in C-E. LN body is lined by awhite dashed line in F-H. DAPI was used to reveal nuclei in F,H. Scalebars: 25 μm in F; 100 μm in H; 150 μm in G; and 250 μm in C-E.

DETAILED DESCRIPTION OF THE INVENTION

It should be understood that this invention is not limited to theparticular methodology, protocols, and reagents, etc., described hereinand, as such, may vary. The terminology used herein is for the purposeof describing particular embodiments only, and is not intended to limitthe scope of the disclosed invention, which is defined solely by theclaims.

The section headings are used herein for organizational purposes onlyand are not to be construed as in any way limiting the subject matterdescribed.

The methods and techniques of the present application are generallyperformed according to conventional methods well-known in the art and asdescribed in various general and more specific references that are citedand discussed throughout the present specification unless otherwiseindicated. See, e.g., Sambrook et al., Molecular Cloning: A LaboratoryManual, 3rd ed., Cold Spring Harbor Laboratory Press, Cold SpringHarbor, N.Y. (2001) and Ausubel et al., Current Protocols in MolecularBiology, Greene Publishing Associates (1992), and Harlow and Lane,Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press,Cold Spring Harbor, N.Y. (1990).

Definitions

“A” or “an” means herein one or more than one; at least one. Where theplural form is used herein, it generally includes the singular.

The term “bandage” as used in this application is synonymous with theterms “dressing” or “patch” as they refer to a functionalized substrateto which cells are attached. These devices have been referred to ascell-laden bandages, cell-laden patches, and cell-laden dressings. Inthese embodiments the cells that are attached to the substrate, whenapplied in operable proximity to the wound, leave the patch, dressing,or bandage and migrate to the wound. In some instances thesebandages/patches may be comprised of a coating of plasma polymer. Asmentioned this can be comprised of a functionalized substrate to whichthe cells are attached.

A “clinically-relevant” number of cells refers to a number of cells thatis sufficient to effect a clinical response; that is, a prevention,reduction, amelioration, etc. of an undesirable pathological conditionin a subject. A particular embodiment pertains to a number of cells thatis sufficient to create a master cell bank.

“Co-administer” means to administer in conjunction with one another,together, coordinately, including simultaneous or sequentialadministration of two or more agents.

“Comprising” means, without other limitation, including the referent,necessarily, without any qualification or exclusion on what else may beincluded. For example, “a composition comprising x and y” encompassesany composition that contains x and y, no matter what other componentsmay be present in the composition. Likewise, “a method comprising thestep of x” encompasses any method in which x is carried out, whether xis the only step in the method or it is only one of the steps, no matterhow many other steps there may be and no matter how simple or complex xis in comparison to them. “Comprised of and similar phrases using wordsof the root “comprise” are used herein as synonyms of “comprising” andhave the same meaning.

“Comprised of” is a synonym of “comprising” (see above).

“Conditioned cell culture medium” is a term well-known in the art andrefers to medium in which cells have been grown. Herein this means thatthe cells are grown for a sufficient time to secrete the factors thatare effective to achieve any of the results described in thisapplication.

Conditioned cell culture medium refers to medium in which cells havebeen cultured so as to secrete factors into the medium. For the purposesof the present invention, cells can be grown through a sufficient numberof cell divisions so as to produce effective amounts of such factors sothat the medium has the effects. Cells are removed from the medium byany of the known methods in the art, including, but not limited to,centrifugation, filtration, immunodepletion (e.g., via tagged antibodiesand magnetic columns), and FACS sorting.

“Effective amount” generally means an amount which provides the desiredlocal or systemic effect. For example, an effective amount is an amountsufficient to effectuate a beneficial or desired clinical result. Theeffective amounts can be provided all at once in a single administrationor in fractional amounts that provide the effective amount in severaladministrations. The precise determination of what would be consideredan effective amount may be based on factors individual to each subject,including their size, age, injury, and/or disease or injury beingtreated, and amount of time since the injury occurred or the diseasebegan. One skilled in the art will be able to determine the effectiveamount for a given subject based on these considerations which areroutine in the art. As used herein, “effective dose” means the same as“effective amount.”

“Effective route” generally means a route which provides for delivery ofan agent to a desired compartment, system, or location. For example, aneffective route is one through which an agent can be administered toprovide at the desired site of action an amount of the agent sufficientto effectuate a beneficial or desired clinical result.

Use of the term “includes” is not intended to be limiting.

“Increase” or “increasing” means to induce entirely where there was nopre-existing presence or to increase the degree of.

The term “isolated” refers to a cell or cells which are not associatedwith one or more cells or one or more cellular components that areassociated with the cell or cells in vivo. An “enriched population”means a relative increase in numbers of a desired cell relative to oneor more other cell types in vivo or in primary culture.

However, as used herein, the term “isolated” does not indicate thepresence of only stem cells. Rather, the term “isolated” indicates thatthe cells are removed from their natural tissue environment and arepresent at a higher concentration as compared to the normal tissueenvironment. Accordingly, an “isolated” cell population may furtherinclude cell types in addition to stem cells and may include additionaltissue components. This also can be expressed in terms of celldoublings, for example. A cell may have undergone 10, 20, 30, 40 or moredoublings in vitro or ex vivo so that it is enriched compared to itsoriginal numbers in vivo or in its original tissue environment (e.g.,bone marrow, peripheral blood, adipose tissue, etc.).

“MAPC” is an acronym for “multipotent adult progenitor cell.” It refersto a cell that is not an embryonic stem cell or germ cell but has somecharacteristics of these. MAPC can be characterized in a number ofalternative descriptions, each of which conferred novelty to the cellswhen they were discovered. They can, therefore, be characterized by oneor more of those descriptions. First, they have extended replicativecapacity in culture without being transformed (tumorigenic) and with anormal karyotype. Second, they may give rise to cell progeny of morethan one germ layer, such as two or all three germ layers (i.e.,endoderm, mesoderm and ectoderm) upon differentiation. Third, althoughthey are not embryonic stem cells or germ cells, they may expressmarkers of these primitive cell types so that MAPCs may express one ormore of Oct 3/4 (aka, Oct 3A or Oct 4), rex-1, and rox-1. They may alsoexpress one or more of sox-2 and SSEA-4. Fourth, like a stem cell, theymay self-renew, that is, have an extended replication capacity withoutbeing transformed. This means that these cells express telomerase (i.e.,have telomerase activity). Accordingly, the cell type that wasdesignated “MAPC” may be characterized by alternative basiccharacteristics that describe the cell via some of its novel properties.

The term “adult” in MAPC is non-restrictive. It refers to anon-embryonic somatic cell. MAPCs are karyotypically normal and do notform teratomas or other tumors in vivo. This acronym was first used inU.S. Pat. No. 7,015,037 to describe a pluripotent cell isolated frombone marrow. However, cells with pluripotential markers and/ordifferentiation potential have been discovered subsequently and, forpurposes of this invention, may be equivalent to those cells firstdesignated “MAPC.” Descriptions of the MAPC type of cell are provided inthe Summary of the Invention above.

MAPC represents a more primitive progenitor cell population than MSC(Verfaillie, C. M., Trends Cell Biol 12:502-8 (2002), Jahagirdar, B. N.,et al., Exp Hematol, 29:543-56 (2001); Reyes, M. and C. M. Verfaillie,Ann N Y Acad Sci, 938:231-233 (2001); Jiang, Y. et al., Exp Hematol,30896-904 (2002); and Jiang, Y. et al., Nature, 418:41-9. (2002).

“Progenitor cells” are cells produced during differentiation of a stemcell that have some, but not all, of the characteristics of theirterminally-differentiated progeny. Defined progenitor cells, such as“cardiac progenitor cells,” are committed to a lineage, but not to aspecific or terminally differentiated cell type. The term “progenitor”as used in the acronym “MAPC” does not limit these cells to a particularlineage. A progenitor cell can form a progeny cell that is more highlydifferentiated than the progenitor cell.

Selection could be from cells in a tissue. For example, in this case,cells would be isolated from a desired tissue, expanded in culture,selected for a desired characteristic, and the selected cells furtherexpanded.

“Self-renewal” refers to the ability to produce replicate daughter stemcells having differentiation potential that is identical to those fromwhich they arose. A similar term used in this context is“proliferation.”

“Serum-free medium” refers to medium in which serum is not present or,if present, is at levels at which the components of the serum have noeffect on the growth or variability of the cells (i.e., are not actuallynecessary, such as residual or trace amounts).

“Stem cell” means a cell that can undergo self-renewal (i.e., progenywith the same differentiation potential) and also produce progeny cellsthat are more restricted in differentiation potential.

“Subject” means a vertebrate, such as a mammal, such as a human Mammalsinclude, but are not limited to, humans, dogs, cats, horses, cows, andpigs.

As used herein, the term “wound” means a breach in the integrity of atissue, e.g., skin, which can be caused by acute trauma or underlyingpathological causes such as the cutaneous and subcutaneous wounds thathave been described in this application.

Wounds may be derived from sources including, but not limited to,autoimmune-disease, rejection of transplanted organs, burns, cuts,lacerations, and ulcerations, including skin ulcerations and diabeticulcerations.

The stem cells may be administered to an animal to repair epithelialdamage caused by burns, cuts, lacerations, and ulcerations, including,but not limited to, skin ulcerations and diabetic ulcerations.

Examples of wounds may include both open and closed wounds. In certainembodiments, the wound comprises an external wound. In certainembodiments, the wound comprises an open wound. In certain embodiments,the wound comprises a chronic wound. In certain embodiments, the woundcomprises a chronic wound or an ulcer.

In certain embodiments, the composition is suitable for topicalapplication, topical administration or topical delivery to a subject.Topical formulations are as described herein. Other forms of delivery ofcells are contemplated.

The dose and frequency of topical administration may be determined byone of skill in the art.

Examples of forms for topical administration include delivery by way ofa gel, an ointment, a cream, a lotion, a foam, an emulsion, asuspension, a spray, an aerosol, a solution, a liquid, a powder, asemi-solid, a gel, a jelly, a suppository; a solid, an ointment, apaste, a tincture, a liniment, a patch, or release from a bandage, gauzeor dressing. Other forms of topical delivery are contemplated.

Methods for incorporating substrates into products for topical releaseare known in the art, for example as described in Boateng J. S. et al(2008) “Wound healing dressings and drug delivery systems: a review” J.Pharm Sci. 97(8): 2892-2923 and “Delivery System Handbook for PersonalCare and Cosmetic Products: Technology” (2005) by Meyer Rosen, publishedWilliam Andrew Inc, Norwich N.Y.

In certain embodiments, the composition is suitable for delivery to asubject by one or more of intravenous administration, by aerosolizedadministration, by parenteral administration, by implant, bysubcutaneous injection, intraarticularly, rectally, intranasally,intraocularly, vaginally, or transdermally.

In certain embodiments, the composition comprises other compounds thatenhance, stabilize or maintain the activity of the cells for deliveryand/or their delivery or transfer.

In certain embodiments, it may be desirable to administer thecomposition by injection. Forms suitable for injectable use includesterile aqueous solutions or dispersions and sterile powders for theextemporaneous preparation of sterile injectable solutions ordispersions. A carrier can be a solvent or dispersion medium containing,for example, water, ethanol, polyol (e.g., glycerol, propylene glycoland liquid polyethylene glycol), suitable mixtures thereof, andvegetable oils.

In certain embodiments, it may be desirable to administer thecomposition intravenously. Compositions containing the compositiondescribed herein suitable for intravenous administration may beformulated by a skilled person.

In certain embodiments, the subject is a human or animal subject. Incertain embodiments, the subject is a human subject.

In certain embodiments, the subject is a mammalian subject, a livestockanimal (such as a horse, a cow, a sheep, a goat, a pig), a domesticanimal (such as a dog or a cat) and other types of animals such asmonkeys, rabbits, mice, laboratory animals, birds and fish. Other typesof animals are contemplated. Veterinary applications of the presentdisclosure are contemplated. Use of any of the aforementioned animals asanimal models is also contemplated.

The present disclosure provide a method of healing or treating a wound,the method comprising delivering cells to the wound using a product or acomposition as described herein.

MAPC

Human MAPCs are described in U.S. Pat. No. 7,015,037. MAPCs have beenidentified in other mammals. Murine MAPCs, for example, are alsodescribed in U.S. Pat. No. 7,015,037. Rat MAPCs are also described inU.S. Pat. No. 7,838,289. These references are incorporated by referencefor describing MAPCs, their phenotype and culture.

Isolation and Growth of MAPCs

Methods of MAPC isolation are known in the art. See, for example, U.S.Pat. No. 7,015,037, and these methods, along with the characterization(phenotype) of MAPCs, are incorporated herein by reference. MAPCs can beisolated from multiple sources, including, but not limited to, bonemarrow, placenta, umbilical cord and cord blood, muscle, brain, liver,spinal cord, blood or skin. It is, therefore, possible to obtain bonemarrow aspirates, brain or liver biopsies, and other organs, and isolatethe cells using positive or negative selection techniques available tothose of skill in the art, relying upon the genes that are expressed (ornot expressed) in these cells (e.g., by functional or morphologicalassays such as those disclosed in the above-referenced applications,which have been incorporated herein by reference).

Rodent MAPCs have also been obtained by improved methods described inBreyer et al., Experimental Hematology, 34:1596-1601 (2006) andSubramanian et al., Cellular Programming and Reprogramming: Methods andProtocols; S. Ding (ed.), Methods in Molecular Biology, 636:55-78(2010), incorporated by reference for these methods. Human MAPCs havebeen obtained by improved methods that are described in Roobrouck et al.Stem Cells 29:871-882 (2011), incorporated by reference for thesemethods.

MAPCs from Human Bone Marrow as Described in U.S. Pat. No. 7,015,037

MAPCs do not express the common leukocyte antigen CD45 or erythroblastspecific glycophorin-A (Gly-A). The mixed population of cells wassubjected to a Ficoll Hypaque separation. The cells were then subjectedto negative selection using anti-CD45 and anti-Gly-A antibodies,depleting the population of CD45⁺ and Gly-A⁺ cells, and the remainingapproximately 0.1% of marrow mononuclear cells were then recovered.Cells could also be plated in fibronectin-coated wells and cultured asdescribed below for 2-4 weeks to deplete the cells of CD45⁺ and Gly-A⁺cells. In cultures of adherent bone marrow cells, many adherent stromalcells undergo replicative senescence around cell doubling 30 and a morehomogenous population of cells continues to expand and maintains longtelomeres.

Alternatively, positive selection could be used to isolate cells via acombination of cell-specific markers. Both positive and negativeselection techniques are available to those of skill in the art, andnumerous monoclonal and polyclonal antibodies suitable for negativeselection purposes are also available in the art (see, for example,Leukocyte Typing V, Schlossman, et al., Eds. (1995) Oxford UniversityPress) and are commercially available from a number of sources.

Techniques for mammalian cell separation from a mixture of cellpopulations have also been described by Schwartz, et al., in U.S. Pat.No. 5,759,793 (magnetic separation), Basch et al., 1983 (immunoaffinitychromatography), and Wysocki and Sato, 1978 (fluorescence-activated cellsorting).

Cells may be cultured in low-serum or serum-free culture medium.Serum-free medium used to culture MAPCs is described in U.S. Pat. No.7,015,037. Commonly-used growth factors include but are not limited toplatelet-derived growth factor and epidermal growth factor. See, forexample, U.S. Pat. Nos. 7,169,610; 7,109,032; 7,037,721; 6,617,161;6,617,159; 6,372,210; 6,224,860; 6,037,174; 5,908,782; 5,766,951;5,397,706; and 4,657,866; all incorporated by reference for teachinggrowing cells in serum-free medium.

Additional Culture Methods

In additional experiments the density at which MAPCs are seeded can varyfrom about 100 cells/cm² or about 150 cells/cm² to about 10,000cells/cm², including about 200 cells/cm² to about 1500 cells/cm² toabout 2000 cells/cm². The density can vary between species.Additionally, optimal density can vary depending on culture conditionsand source of cells. It is within the skill of the ordinary artisan todetermine the optimal seeding density for a given set of cultureconditions.

Also, effective atmospheric oxygen concentrations of less than about10%, including about 1-5% and, especially, 3-5%, can be used at any timeduring the isolation, growth and differentiation of MAPCs in culture.

Cells may be cultured under various serum concentrations, e.g., about2-20%. Fetal bovine serum may be used. Higher serum may be used incombination with lower oxygen tensions, for example, about 15-20%. Cellsneed not be selected prior to adherence to culture dishes. For example,after a Ficoll gradient, cells can be directly plated, e.g.,250,000-500,000/cm². Adherent colonies can be picked, possibly pooled,and expanded.

In one embodiment, high serum (around 15-20%) and low oxygen (around3-5%) conditions are used for the cell culture. For example, adherentcells from colonies can be plated and passaged at densities of about1700-2300 cells/cm² in 18% serum and 3% oxygen (with PDGF and EGF).

In an embodiment specific for MAPCs, supplements are cellular factors orcomponents that allow MAPCs to retain the ability to differentiate intocell types of more than one embryonic lineage, such as, all threelineages. This may be indicated by the expression of specific markers ofthe undifferentiated state, such as Oct 3/4 (a.k.a. Oct4 or Oct 3A)and/or markers of high expansion capacity, such as, telomerase.

For all the components listed below, see U.S. Pat. No. 7,015,037, whichis incorporated by reference for teaching these components.

Stem cells often require additional factors that encourage theirattachment to a solid support, such as fibronectin. One embodiment ofthe present invention utilizes fibronectin. See, for example, Ohashi etal., Nature Medicine, 13:880-885 (2007); Matsumoto et al., J Bioscienceand Bioengineering, 105:350-354 (2008); Kirouac et al., Cell Stem Cell,3:369-381 (2008); Chua et al., Biomaterials, 26:2537-2547 (2005);Drobinskaya et al., Stem Cells, 26:2245-2256 (2008); Dvir-Ginzberg etal., FASEB J, 22:1440-1449 (2008); Turner et al., J Biomed Mater ResPart B: Appl Biomater, 82B:156-168 (2007); and Miyazawa et al., Journalof Gastroenterology and Hepatology, 22:1959-1964 (2007)).

Once established in culture, cells can be used fresh or frozen andstored as frozen stocks, using, for example, DMEM with 20%-40% FCS and10% DMSO. In one embodiment, 20% FCS is used. Other methods forpreparing frozen stocks for cultured cells are also available to thoseof skill in the art.

For the purposes of this application, the additional culture methods aswell as the other culture methods also apply to bioreactor methods, withrespect to the medium components and conditions described above. As anexample, in an exemplified embodiment, the oxygen concentration is 5%,serum is about 19% and both EGF and PDGF are added to the medium.

Pharmaceutical Formulations

U.S. Pat. No. 7,015,037 is incorporated by reference for teachingpharmaceutical formulations. In certain embodiments, the cellpopulations are present within a composition adapted for and suitablefor delivery, i.e., physiologically compatible.

In some embodiments the purity of the cells (or conditioned medium) foradministration to a subject is about 100% (substantially homogeneous).In other embodiments it is 95% to 100%. In some embodiments it is 85% to95%. Particularly, in the case of admixtures with other cells, thepercentage can be about 10%-15%, 15%-20%, 20%-25%, 25%-30%, 30%-35%,35%-40%, 40%-45%, 45%-50%, 60%-70%, 70%-80%, 80%-90%, or 90%-95%. Orisolation/purity can be expressed in terms of cell doublings where thecells have undergone, for example, 10-20, 20-30, 30-40, 40-50 or morecell doublings.

The choice of formulation for administering the cells for a givenapplication will depend on a variety of factors. Prominent among thesewill be the species of subject, the nature of the condition beingtreated, its state and distribution in the subject, the nature of othertherapies and agents that are being administered, the optimum route foradministration, survivability via the route, the dosing regimen, andother factors that will be apparent to those skilled in the art. Forinstance, the choice of suitable carriers and other additives willdepend on the exact route of administration and the nature of theparticular dosage form.

Final formulations of the aqueous suspension of cells/medium willtypically involve adjusting the ionic strength of the suspension toisotonicity (i.e., about 0.1 to 0.2) and to physiological pH (i.e.,about pH 6.8 to 7.5). The final formulation will also typically containa fluid lubricant.

In some embodiments, cells/medium are formulated in a unit dosageinjectable form, such as a solution, suspension, or emulsion.Pharmaceutical formulations suitable for injection of cells/mediumtypically are sterile aqueous solutions and dispersions. Carriers forinjectable formulations can be a solvent or dispersing mediumcontaining, for example, water, saline, phosphate buffered saline,polyol (for example, glycerol, propylene glycol, liquid polyethyleneglycol, and the like), and suitable mixtures thereof.

The skilled artisan can readily determine the amount of cells andoptional additives, vehicles, and/or carrier in compositions to beadministered in methods of the invention. Typically, any additives (inaddition to the cells) are present in an amount of 0.001 to 50 wt % insolution, such as in phosphate buffered saline. The active ingredient ispresent in the order of micrograms to milligrams, such as about 0.0001to about 5 wt %, preferably about 0.0001 to about 1 wt %, mostpreferably about 0.0001 to about 0.05 wt % or about 0.001 to about 20 wt%, preferably about 0.01 to about 10 wt %, and most preferably about0.05 to about 5 wt %.

Example MAPC Support Lymphatic Vessel Growth in Lymphedema

MAPCs have Lymphvasculogenic and Lymphangiogenic Potential

The inventors investigated whether MAPCs have the inherent capacity togive rise to LECs. First, they confirmed that MAPCs gain expression ofgeneral EC markers upon VEGF-A exposure (FIGS. 1A, B). Prox1, themasterswitch of lymphatic differentiation, was significantly induced inMAPCs at 2 w of endothelial differentiation and its expression levelsremained stable until 1 w later (FIGS. 1A,B). Prox1 induction may alsohave triggered expression of additional lymphatic genes (i.e., Pdpn andItg9a), known to be upregulated by forced Prox1 expression (36). Afraction (21±6%) of MAPCs exposed to VEGF-A also expressed LYVE1 (shownat the protein level for mMAPCs; FIG. 1C). Notably, induction oflymphatic marker gene expression in hMAPCs was not further improved inthe presence of lymphangiogenic GF VEGF-C (shown for LYVE1 in FIG. 1D;PROX1 fold-induction versus d0 was also comparable upon exposure toVEGF-A, VEGF-C or a combination: 26±10, 26±14 and 26±11, respectively;n=4). COUP-TFII, a transcription factor co-determining lymphaticcompetence of ECs (36,37), was expressed at high relatively constantlevels throughout the differentiation process (not shown). Thus, MAPCshave the inherent capacity to initiate a LEC differentiation program.

The inventors reasoned that MAPCs might have an effect onlymphangiogenesis by cross-talking to LECs, as MAPCs are known tosecrete VEGF-A, which is responsible for the trophic effects of MSCs onLECs. 72 h MAPC supernatant significantly stimulated LEC sprouting,proliferation and migration (FIGS. 1E-M). Thus, MAPCs may support theformation of lymphatic vessels by a combination of direct and indirecteffects.

MAPCs Contribute to Physiological Lymphangiogenesis During Wound Healing

Wound healing requires growth of new blood and lymphatic vessels(Maruyama, K., et al. 2007. Am J Pathol (2007) 170:1178-1191).Transplantation of mMAPCs from mice ubiquitously expressing enhanced(e)GFP shortly after a linear back skin incision in C57Bl/6 miceresulted in a significant acceleration of wound closure (FIG. 2A andFIG. 7A) and the occurrence of smaller scars (FIG. 7B-E) compared toPBS-injection. While all mMAPC-injected wounds were completelyreepithelialized, 60% of PBS-treated wounds were only partially coveredwith neo-epidermis at 10 d. In vivo fluorescence imaging revealed that 4d after injection, eGFP⁺ mMAPCs were located in close vicinity to bloodvessels growing towards the wound bed (FIG. 2B). In accordance, mMAPCtransplantation boosted de novo growth of CD31⁺ vessels in the woundcenter by two-fold (number of CD31⁺ vessels/area (mm²): 76±4 inmMAPC-treated versus 36±16 in PBS-injected mice; n=5, P<0.05 byMann-Whitney-U test; FIG. 2C,D). In agreement with earlier limb ischemiastudies (Aranguren, X. L., et al. J Clin Invest (2008) 118:505-514),direct contribution to CD31⁺ ECs was modest in this wound healing modelmMAPCs also significantly increased LYVE1⁺ lymphatic capillary growth by3-fold and occasionally contributed to differentiated LECs (FIGS. 2E-H).The vast majority of LYVE1⁺ cells were lymphatic endothelial cells(LECs) and not macrophage intermediates—previously suggested tocontribute to lymphatic vessels in transplanted kidneys (Kerjaschki, D.,et al. Nat Med (2006) 12:230-234)—since they did not co-localize withCD45, a panleukocytic marker (FIG. 7F).

hMAPCs applied onto circular wounds in athymic nude mice significantlypromoted healing. Live imaging and cross-sections through the wound areaupon transplantation of hMAPCs showed their homogenous distribution inthe wound bed (FIGS. 7G,H). hMAPCs accelerated epithelial coverage (%coverage at 5 d: 46±5 in hMAPC-treated versus 7±2 in vehicle-treatedwounds; n=6, P<0.05 by Mann-Whitney-U test; FIGS. 2I,J). All wounds werecompletely reepithelialized at d10 in hMAPC-treated mice versus only 46%of PBS-treated mice. hMAPC transplantation improved woundvascularization by about two-fold (% CD31⁺ area in the wound borders at5 d and the entire wound at 10 d: 11±1 and 13±1 in hMAPC-treated versus6±1 and 6±1 in PBS-injected wounds; n=6-8, P<0.05 by Student's t-test;FIGS. 2K,L). hMAPCs significantly boosted lymphangiogenesis as evidencedby the three-fold increased LYVE1⁺ fractional area (FIGS. 2M-O). Doubleimmunofluorescence (IF) staining for Prox1 and smooth muscle α-actin(αSMA) revealed that in this short-duration wound model, the vastmajority (97±2%) of lymphatic vessels in the granulation tissue at 10 dwere capillaries devoid of αSMA coverage. Again, in situ LECdifferentiation of hMAPCs happened only occasionally, shown by theco-localization of the hMAPC-derived vimentin signal and LYVE1 staining(FIG. 2P). Thus, MAPCs significantly accelerated wound healing in partby boosting capillary lymphangiogenesis mostly indirectly through atrophic effect on host LECs.

MAPCs Regenerate Lymphatic Vessels in a Secondary Lymphedema Model

To test the potential of MAPCs to restore lymph flow in secondarylymphedema, lymph drainage to the axillary lymph nodes (LNs) wasdiscontinued by means of a full-thickness skin incision in the abdomen(FIG. 3A) (Saaristo, A., et al. FASEB J (2004) 18:1707-1709). Thisabrogated normal lymph drainage in the majority (7/10) of PBS-treatedanimals shown by the lack of fluorescent dye crossing the wound border 2w following skin incision (FIG. 3B; Table 1). MAPC transplantationaround the wound border almost completely (in 5/6 and 6/6 cases formMAPC- or hMAPC-treated mice, respectively) restored lymph drainageacross this border (FIGS. 3C,D; Table 1). While drainage to the axillaryLN was only obtained in 1/10 PBS-injected mice, 3/6 mMAPC-injected and6/6 hMAPC-injected mice showed LN drainage after 2 w. In a second set ofmice injected with PBS or mMAPCs, fluorescent dye crossed the woundborder in 5/5 mMAPC-treated mice and LN drainage was restored in 4/5,while there was no restoration of drainage across the wound border andinto the axillary LN in any of the PBS-injected mice 4 w after skinincision (Table 1). Histological analysis of the skin wound area aroundthe transplantation sites revealed that, in addition to a 1.8-foldexpansion of CD31⁺ blood vessels (FIGS. 8A-D), MAPC-injected mice had a˜two-three-fold increase in Flt4⁺ (VEGFR3⁺) and LYVE1⁺ fractional areain the wound borders (FIGS. 4A-D+8E-H, respectively) 2 w after skinincision. The average number of functional lymphatic vessels percross-section filled with fluorescently-labeled dextran around theincision at 2 w was significantly increased by MAPC injection (FIGS.4E-H). Notably, some mMAPCs persisted until 2-4 w, lodged in thevicinity of draining lymphatic vessels and occasionally became part oftheir endothelial lining (FIGS. 4I-L). Compared to the wound healingmodels, deep (sparsely) αSMA-coated Prox1⁺ (pre-)collector vessels weremore frequently observed here (FIG. 8I), yet the majority (67±5%) ofskin lymphatics was still devoid of αSMA coating. Nevertheless, hMAPCtransplantation significantly increased the number of draining(pre-)collectors by 3-fold (Table 1). Thus, MAPCs restored the lymphaticfunctional deficit in secondary lymphedema by bridging the gap in thepre-existing lymphatic network across the wound border.

MAPCs Reconnect Transplanted Lymph Nodes to the Host Lymphatic Network

Thus far, the results show that MAPC transplantation increaseslymphangiogenesis and restores lymphatic drainage mainly by boostinglymphatic capillary growth. However, the underlying problem of secondarylymphedema most often relates to damaged LNs and lymphatic collectors towhich the lymphatic capillaries normally connect. Hence, an appropriateremedy must not only imply lymphatic capillary expansion but alsorestoration of lymphatic collector vessels. A stringent model wasapplied in which axillary LNs and their surrounding lymphatic(collector) network are surgically ablated, such that drainage of a LNtransplanted in this area becomes critically dependent on restoration oflymphatic collectors and their reconnection to the distant lymphaticnetwork (Tammela, T., et al. Nat Med (2007) 13:1458-1466). To test thepotential of hMAPCs, they were applied in Matrigel® around atransplanted LN derived from mice ubiquitously expressing dsRed or eGFPin the right axillary cavity (FIG. 5A). Transplantation of the LN alone(and covering it with Matrigel® containing PBS) failed to resolveinflammation-induced edema in the right upper limb, evident from theaccumulation of interstitial fluid measured by magnetic resonanceimaging (MRI) 4 w and 16 w after surgery upon challenge of the paw withmustard oil—an inflammatory agent (FIGS. 5B,C+9A). At 16 w, fluidaccumulation was significantly less prominent upon application of hMAPCsaround the transplanted LN, suggesting functional restoration of lymphdrainage from the front paw to the axillary region (FIGS. 5B,D+9B).Indeed, lymphangiography revealed that lymph fluid drainage wassignificantly improved in hMAPC-treated mice and that the injectedfluorescent dye reached the transplanted LN in ˜35% and 50-60% ofhMAPC-treated mice, 8 w and 16 w after transplantation, respectively, aresult that was reproduced with two hMAPC clones and not at all withPBS-treated mice (FIGS. 5E-G+9C; Table 2). This suggested that hMAPCtransplantation was able to functionally reconnect the transplanted LNto the distant lymphatic network. Notably, while all LNs implanted alongwith hMAPCs persisted, half of them could not be found back inPBS-injected mice at 16 w, suggesting a positive effect of hMAPCtransplantation on LN survival (Table 2). Moreover, unlike inhMAPC-treated mice, the mean size of the transplanted LN was decreasedin PBS-treated mice (Table 2). Inspection of the skin area leading up tothe transplanted LN revealed a two-fold more elaborate blood vascularnetwork in hMAPC-treated mice (FIGS. 6A-C) with significantly more bloodvessels in the immediate surroundings of the LNs, compared toPBS-injected mice (FIGS. 6D+9D,E). Some hMAPCs persisted until 16 w andwere found in the vicinity of the transplanted LN (FIG. 9F). Alltransplanted LNs in hMAPC-treated mice showed signs of (outward)branching of their internal (lymph)vascular network from 4 w onwards,while this was never observed in PBS-treated mice (FIGS. 6E-G+9G,H;Table 2). At 8 w, hMAPC transplantation resulted in a significant 4-foldexpansion of LYVE1⁺ lymphatic vessels in the area surrounding the LN ascompared to PBS-treatment (FIGS. 6H-J). Finally, to test whether thebeneficial effect of hMAPCs was related to functional reconnection oflymphatic collector vessels, αSMA/Prox1 IF stainings were performed oncross-sections taken from the area around the transplanted LNs and foundlymph-filled Prox1⁺αSMA⁺ collectors (FIGS. 6K-M). Collector identity wasconfirmed by negative staining for LYVE1 (FIG. 6N). Collectively, hMAPCsrestored lymph drainage following LN transplantation by promoting LNsurvival and outward branching and by reconnecting the transplanted LNto the endogenous vessel network through collector vessels.

Methods

MAPC Derivation and Differentiation

The mMAPC clone was derived from BM of adult C57Bl/6 mice withubiquitous eGFP expression (C57Bl/6-Tg-eGFP). mMAPCs were derived andmaintained under low O₂ (5%) and low-serum (2%) conditions, as described(Aranguren, X. L., et al. 2008. J Clin Invest (2008) 118:505-514). hMAPCclones were established according to derivation and culture methodsdescribed earlier (Roobrouck, V. D., et al. Stem Cells (2011)29:871-882). Cell cultures were routinely tested for mycoplasmacontamination. Endothelial differentiation was performed by exposure torecombinant (r)hVEGF-A₁₆₅ or rhVEGF-C(R&D Systems), as described(Roobrouck, V. D., et al. Stem Cells (2011) 29:871-882). The referencesthat describe the MAPC derivation above are incorporated by referencefor these methods.

Human MAPCs were isolated from bone fragments (femur) and hMab isolatedfrom skeletal muscle fragments (quadriceps femoris) of children (5- to15-year old) undergoing orthopedic surgery, after obtaining informedconsent in accordance with the guidelines of the Medical EthicsCommittee of the University Hospitals Leuven. hMAPCs were generated byflushing the bone fragment and plating the total cell fraction at0.5×10⁶ cells per centimeter square in medium consisting of 60%Dulbecco's modified Eagle's medium (DMEM) low glucose (Gibco,Invitrogen, Carlsbad, Calif., www.invitrogen.com), 40% MCDB-201(Sigma-Aldrich, St. Louis, Mo., www.sigmaaldrich.com), supplemented with50 nM dexamethasone, 10⁻⁴ M L-ascorbic acid,1×selenium-insulin-transferrin (ITS), 0.5×linoleic acid-bovine serumalbumin (all from Sigma-Aldrich), 1% penicillin/streptomycin (Gibco,Invitrogen), along with 2% Serum Supreme (Lonza BioWhittaker, Basel,Switzerland www.Lonza.com), and human platelet derived growth factor BB(PDGF-BB) (R&D Systems, Minneapolis, Minn., www.mdsystems.com) and humanEGF (Sigma-Aldrich) (both 10 ng/ml). Human MAPC cultures were maintainedunder hypoxic conditions (5% O₂) in a 5.5% CO₂ humidified incubator at adensity of 400 cells per centimeter square and were passaged every 2-3days. Clonal populations were obtained by plating 5 cells per well in a96-well or 48-well plate between passages 2 and 12.

Isolation and culture of the cells can also be performed as previouslydescribed in Reyes, M., et al. J Clin Invest (2002) 109:337-346. Bonemarrow is obtained from healthy donors. Bone marrow mononuclear cellsobtained by Ficoll-Paque density gradient centrifugation are depleted ofCD45⁺ and glycophorinA⁺ cells by means of micromagnetic beads. Theeluted cells are 99.5% negative for both CD45 and glyA. Cells are platedinto 96-well plates at a concentration of 5×10³ cells/200 μl. This isdone in the same medium described above. When cells are around 50%confluent they are trypsinized and passaged into bigger plates at aconcentration of 2×10³-8×10³/cm² and further expanded. Isolation andculture of the cells can also be performed as previously described inReyes et al. Blood 98:2615-2625. The method is essentially the same asthat just described except that, after collecting the cells that areglyA⁻ and CD45,⁻ cells can be plated into 96-well plates at aconcentration of 5-10×10³/ml. In all these conditions the medium is thesame. These references are incorporated by reference for reportingmethods for the isolation and culture of the cells.

Murine cells were derived from BM of C57BL/6 mice with ubiquitous GFPexpression. mMAPCs were derived and maintained under low O₂ (5%) andlow-serum (2%) conditions (Ulloa-Montoya, F., et al. Genome Biol. (2007)8:R163). The mMAPCs can also be derived according to Breyer et al.Experimental Hematology 34:1596-1601 (2006). These references areincorporated by reference for providing the methods of deriving thecells.

RNA Isolation, cDNA Preparation, qRT-PCR and Flow Cytometry

Total RNA from cell lysates was extracted using Trizol® reagent(Invitrogen) or RLT lysis buffer (Qiagen). mRNA was reverse transcribedusing Superscript III Reverse Transcriptase (Invitrogen) and cDNAunderwent 40 amplification rounds (primer sequences are listed in Table3) on an ABI PRISM 7700 cycler, PerkinElmer/Applied Biosystems) forSYBR-Green-based qRT-PCR, as described (Aranguren, X. L., et al. J CellSci (2013) 126:1165-1175). mRNA levels were normalized using GAPDH ashousekeeping gene. To analyze LYVE1 expression on the surface ofdifferentiated mMAPCs, cells were harvested by gentle trypsinization andanalyzed by FACS as described in the extended methods.

In Vitro LEC Functional Assays

Cell culture and CM collection. Human lung LECs were purchased fromLonza (Merelbeke, Belgium) and cultured in EBM2 supplemented withEGM-2-MV bulletkit (Lonza). For CM collection, MAPCs were seeded at highdensity in serum-free basal media and CM was collected after 72 h andfrozen in aliquots at −80° C. until further use.

LEC proliferation. LECs were seeded at 2,000 cells/cm² in regular LECgrowth medium onto gelatin-coated 96-well plates. Following theirattachment, medium was replaced by a 1:1 mix of serum-free LEC mediumand MAPC-CM or 100% serum-free LEC medium as reference condition. After24 h, cell proliferation was assessed with the WST-1 cell proliferationassay kit (Cayman Chemical).

LEC migration. Transwell inserts (containing polycarbonate filters with8 μm pore size; Costar, Corning) were coated overnight with gelatin. Thebottom compartment of a 24-well plate was filled with non-conditionedmedia (NCM) or MAPC-CM. Following rehydration, inserts were placed intothe 24-well plate and each was loaded with EGM-2-MV/0.5% FBS containing5×10⁴ LECs. Following incubation for 24 h at 37° C./5% CO₂, cells werefixed in methanol and stained with Wright-Giemsa's staining solution(Sigma WG32). Inserts were lifted and cells on the upper side of themembranes were removed. Pictures of the inserts were taken andtransmigrated cells were manually counted.

LEC sprouting. LEC spheroids were allowed to form by applying 25 μldroplets (containing 1,000 LECs in a 20% methylcellulose/EGM-2-MVmixture) onto non-attachment plates and incubating them upside down at37° C./5% CO₂. The next day, spheroids were carefully washed in PBS/2%FBS, collected by gentle centrifugation, resuspended inmethylcellulose/FBS/collagen (Purecol Advanced Biomatrix) and seededinto 24-well plates. Following incubation for 30 min at 37° C./5% CO₂,mMAPC-CM (1:1 mix with serum-free LEC media) or 100% serum-free LECmedia as reference condition was added on top of the collagen/spheroidgel. Pictures were taken 24 h later and the number of sprouts perspheroid was determined by manual counting.

Mouse Models

As MAPCs do not express MHC-I and—consequently—are sensitive to NKcell-mediated clearance, all mice were injected i.p. with anti-asialoGM1 Ab's (Wako Chemicals, Osaka, Japan) 1-2 h before transplantation andevery 10 d thereafter. These antibodies selectively eliminate NK cellswithout affecting macrophage or lymphocyte function (Seaman, W. E., etal. J Immunol (1987) 138:4539-4544).

Linear wound model: At day 0, a 12-mm linear skin incision was inflictedon the back of anesthetized 12-w-old C57Bl/6 male mice Immediately afterwounding, mice were injected in the muscle fascia underneath the skinwound with 1×10⁶ mMAPCs (resuspended in PBS) or PBS alone divided overthree equally spaced injection spots. To avoid wound infection, micewere housed individually in cages without bedding. Wound dimensions weremeasured daily under anesthesia using digital calipers (VWRI819-0012,VWR). At d4, brightfield and fluorescence pictures of the wound areawere taken and at d10, mice were euthanized, the residual skin wound andunderlying muscle tissue were dissected out, fixed and prepared forembedding.

Circular wound model: At day 0, 12-w-old athymic nude Foxn1 male mice(Harlan) were anesthetized and under sterile and temperature-controlled(37° C.) conditions, standardized full-thickness wounds were made with a0.5 cm biopsy puncher (Stiefel Laboratories, Offenbach am Main, Germany)on the back of the mouse. A silicone ring was sutured around the woundand wounds were treated with PBS or 5×10⁵ hMAPCs. In a subset of mice,hMAPCs were transduced with an eGFP-encoding lentivirus beforetransplantation. An occlusive dressing (Tegaderm™, 3M, Diegem, Belgium)was used to keep the wound moist and was renewed every other day. At 5 dor 10 d after wounding, mice were euthanized, skin wounds were dissectedout, rinsed and post-fixed. Following fixation, skin fragments wereseparated in two equal pieces at the midline of the wound and processedfor embedding.

Skin flap model: At day 0, 12-w-old athymic nude Foxn1 male mice(Harlan) were anesthetized and the lymphatic network in the abdominalskin was severed by elevating an epigastric skin flap and suturing itback to its original position, as described (Saaristo, A., et al. FASEBJ (2004) 18:1707-1709). Continuous blood supply to the flap was insuredby retaining a vascular pedicle (FIG. 3A). One day after resuturing theskin flap, 1×10⁶ mMAPCs, 1×10⁶ hMAPCs or PBS (divided over 4 injectionspots; FIG. 3A) were injected around the wound edges. Two or 4 w later,the axillary regions were exposed and axillary LN drainage was monitoredby microlymphangiography after intradermal injection of FITC-dextran (MW2,000 kDa, Sigma-Aldrich; hMAPCs) or Rhodamin-B-isothiocyanate-dextran(MW 70 kDa, Sigma-Aldrich; mMAPCs) under the wound border (FIG. 3A).Brightfield and fluorescence pictures were taken at 15 min and mice weresubsequently euthanized, the skin wound area around the cellengraftment/microlymphangiography areas excised, fixed and processed forembedding.

LN transplantation model: At day 0, 12-w-old athymic nude Foxn1 femalemice (Harlan) were anesthetized and to visualize the LNs, the rightaxilla region was exposed and mice were injected with a 3% Evans Bluesolution in the palm of the right paw after which LNs were removed(along with the surrounding lymphatic (collector) vessels). A pocketjust caudal of the axillary vessels was prepared. Donor LNs weredissected from mice ubiquitously expressing DsRed(B6.Cg-Tg(CAG-DsRed*MST)1Nagy/J; for mice receiving hMAPCs or PBS andfollowed up for 4 w or 8 w) or enhanced (e)GFP(C57BL/6-Tg(CAG-EGFP)1Osb/J; for mice receiving hMAPCs or PBS andfollowed up for 4 w or 16 w) and cut in two halves through the hilus.The cut LN was subsequently implanted into the recipient pocket andfixed in place with permanent sutures (Monosof™). Cold GF-reducedMatrigel® (Beckton Dickinson) mixed with 0.5×10⁶ hMAPCs or PBS wasapplied into the pocket and allowed to solidify. The skin wassubsequently closed and the wound covered with Tegaderm™ dressing. Four,eight or sixteen weeks later, mice were anesthetized and subjected tomicrolymphangiography following injection of FITC-conjugated L.esculentum lectin (Vector Laboratories; in DsRed⁺ LN recipients) orTexas Red-conjugated L. esculentum lectin (in eGFP⁺ LN recipients) inthe palm of the right paw. Drainage of the implanted LN was monitoredfor 15 min and brightfield and fluorescence pictures were taken at theend. Mice were subsequently euthanized, the axilla regions containingthe transplanted LN excised, fixed and processed for embedding. Twoadditional sets of mice were subjected to in vivo MRI, followinginflammatory stimulation by injection of mustard oil (to elicit vascularhyperpermeability and aggravate edema), as described in the extendedmethods.

Histology and Morphometry

Morphometric analyses were performed on 7 μm paraffin sections, 10 μmcryosections or brightfield pictures of exposed skin regions by blindedobservers. Lymphatic (determined on LYVE1-, Flt4- or Prox1/αSMA-stainedsections) or blood (determined on CD31-stained sections) vessel densityand epithelial coverage (determined on pancytokeratin-stained sections)was scored on at least 10 randomly chosen fields per mouse, covering adistance of 700 μm. Functional lymphatics (determined on cryosections ofmice injected with fluorescently-labeled dextran) were counted on 8-10consecutive sections per mouse, thereby scanning the entire wound areavisible on each section. The fractional area of the blood vessel networkleading up to the transplanted LNs was determined on digitallyreconstructed images of the entire region of interest. For stainings onparaffin sections, slides were deparaffinated and rehydrated,cryosections were incubated in PBS for five min prior to the stainingprocedure. H&E staining was performed as previously described(Aranguren, X. L., et al. J Clin Invest (2008) 118:505-514). IF and IHCstaining procedures for CD31, Flt4, pancytokeratin, LYVE1 (combined ornot with CD45 or vimentin), Prox1/αSMA, vimentin and (Prox1/)eGFP aredescribed in the supplement and a list of primary Ab's is provided inTable 4. All Images were recorded on a Zeiss Axiovert 200M microscope, aZeiss Axio Imager Z1 or a Zeiss LSM510 confocal microscope equipped witha Zeiss MRc5 camera and Axiovision 4.8 software.

Statistics

n in results text and Figure/Table legends designates the number ofreplicates (i.e., each performed on different passages of a given MAPCclone; in vitro) or separate animals (in vivo). Data normality wastested by the Shapiro-Wilk test. Comparisons among two groups wasperformed by Student's t-test in case of normal distribution or byMann-Whitney-U test in cases where data were not normally distributed ornormality could not be assumed. Multiple-group comparisons were done by1-way ANOVA with Tuckey's post-hoc test (normal distribution) orKruskal-Wallis test with Dunn's post-hoc test (no normality assumption).Wound size was evaluated by repeated measure ANOVA, followed by Fisherleast-significant-difference test. All analyses were performed withGraphpad Prism (version 6.0).

Extended Methods

MAPC Derivation and Differentiation

The murine (m)MAPC clone was derived from BM of adult C57Bl/6 mice withubiquitous eGFP expression (C57Bl/6-Tg-eGFP). mMAPCs were derived andmaintained under low O₂ (5%) and low-serum (2%) conditions, aspreviously described (Aranguren, X. L., et al. J Clin Invest (2008)118:505-514). Human (h)MAPC clones were established at KU Leuven (clone1 or hMAPC1 at the Endothelial Cell Biology Unit; clone 2 or hMAPC2 atthe Stem Cell Institute Leuven), according to derivation and culturemethods described earlier (Roobrouck, V. D., et al. Stem Cells (2011)29:871-882). Cell cultures were routinely tested for mycoplasmacontamination. Endothelial differentiation was performed by exposure ofthe cells to recombinant (r)hVEGF-A₁₆₅ or rhVEGF-C (both fromR&DSystems), as described (Roobrouck, V. D., et al. Stem Cells (2011)29:871-882).

RNA Isolation, cDNA Preparation, qRT-PCR and Flow Cytometry

Total RNA from cell lysates was extracted using Trizol® reagent(Invitrogen) or RLT lysis buffer (Qiagen). mRNA was reverse transcribedusing Superscript III Reverse Transcriptase (Invitrogen) and cDNAunderwent 40 amplification rounds on an ABI PRISM 7700 cyclerPerkinElmer/Applied Biosystems) for SYBR-Green-based qRT-PCR, asdescribed (Aranguren, X. L. et al. J Cell Sci (2013) 126:1164-1175).Primer sequences for qRT-PCR are listed in Table 3. mRNA levels werenormalized using GAPDH as housekeeping gene. To analyze LYVE1 expressionon the surface of differentiated mMAPCs, cells were harvested by gentletrypsinization, washed with FACS staining buffer (PBS+1 mmol/L EDTA+25mmol/L HEPES+1% BSA) and incubated with primary antibody (Upstate) orthe corresponding rabbit IgG isotype for 20 min at room temperature inthe dark. After washing with FACS buffer, cells were incubated withbiotinylated goat-anti-rabbit secondary antibodies for 20 min at roomtemperature in the dark. Next, samples were washed and incubated in thedark for 20 min with allophycocyanin (APC)-labeled streptavidin. Toselect for viable cells, 7-AAD was added 10 min before running thesamples on a FACS Aria I (Beckton Dickinson) for analysis.

In Vitro LEC Functional Assays

Cell culture and conditioned media collection. Human lung LECs werepurchased from Lonza (Merelbeke, Belgium) and cultured in EBM2supplemented with EGM-2-MV bulletkit (Lonza). For CM collection, MAPCswere seeded at high density in serum-free basal media and CM wascollected after 72 h and frozen in aliquots at −80° C. until furtheruse.

LEC proliferation. To test the effect of MAPC-CM on LEC proliferation,LECs were seeded at a density of 2,000 cells/cm² in regular LEC growthmedium onto gelatin-coated 96-well plates. Following their attachment,medium was replaced by a 1:1 mix of serum-free LEC medium and MAPC-CM or100% serum-free LEC medium as reference condition. After 24 h, cellproliferation was assessed with the WST-1 Cell Proliferation Assay kit.Briefly, 10 μl of WST-1 mixture was added to each well, cells wereincubated at 37° C. for 2 h and the absorbance of each well was measuredon a Bio-Tek microplate reader (BRS, Belgium) at a wavelength of 450 nm.

LEC migration. To estimate the effect of MAPC-CM on LEC migration, aBoyden chamber assay was performed. Briefly, transwell inserts(containing polycarbonate filters with 8 μm pore size; Costar, Corning)were coated overnight with 0.2% gelatin. The bottom compartment of a24-well plate was filled with 0.3 ml NCM or with 0.3 ml of mMAPC orhMAPC-CM. Following rehydration for 1 h with deionized water, insertswere placed into the 24-well plate and each was loaded with 0.3 mlEGM-2-MV/0.5% FBS containing 5×10⁴ LECs. Following incubation for 24 hat 37° C./5% CO₂, cells were fixed in methanol for 30 min at −20° C.Next, cells were stained with Wright-Giemsa's staining solution (SigmaWG32) for 7 min and rinsed with deionized water for 10 min. Inserts werelifted and cells on the upper side of the membranes were removed bygentle rubbing using a cotton swab. Pictures of the inserts were takenwith a Zeiss MRc5 camera mounted onto an Axiovert200M microscope andequipped with Axiovision 4.8 software, and transmigrated cells weremanually counted in 3 random fields per insert at 20× magnification.

LEC sprouting. To test the effect of mMAPC-CM on LEC sprouting, LECspheroids were allowed to form by applying 25 μl droplets (containing1,000 LECs in a 20% methylcellulose/EGM-2-MV mixture) ontonon-attachment plates and incubating them upside down at 37° C./5% CO₂.The next day, spheroids were carefully washed in PBS/2% FBS, collectedby gentle centrifugation, carefully resuspended inmethylcellulose/FBS/collagen (Purecol Advanced Biomatrix) and seededinto 24-well plates (0.5 ml/well). Following incubation of 30 min at 37°C./5% CO₂, 0.5 ml mMAPC-CM (1:1 mix with serum-free LEC media) or 100%serum-free LEC media as reference condition was added on top of thecollagen/spheroid gel. Pictures were taken 24 h later with a Zeiss MRmcamera mounted on a Zeiss Axiovert200M microscope and the number ofsprouts per spheroid was determined by manual counting.

Mouse Models

As MAPCs do not express MHC-I and—consequently—are sensitive to NKcell-mediated clearance, all mice were injected i.p. with 20 μlanti-asialo GM1 Ab's (Wako Chemicals, Osaka, Japan; 20× diluted in PBS)1-2 h before transplantation and every 10 d thereafter. These antibodiesselectively eliminate NK cells without affecting macrophage orlymphocyte function (Seaman, W. E., et al. J Immunol (1987)138:4539-4544).

Linear wound model: At day 0, a 12-mm linear skin incision was inflictedwith a scalpel on the back of 12-w-old C57Bl/6 male mice after they wereanesthetized with a mixture of 100 mg/kg ketamine and 10 mg/kg xylazineImmediately after wounding, mice were injected in the muscle fasciaunderneath the skin wound with 1×10⁶ mMAPCs (resuspended in PBS) or PBSalone divided over three equally spaced injection spots. To avoid woundinfection, mice were housed individually in cages without bedding. Wounddimensions were measured daily under isoflurane anesthesia using digitalcalipers (VWRI819-0012, VWR). At day 4, brightfield and fluorescencepictures of the wound area were taken with a Zeiss MRc5 camera mountedon a Zeiss Lumar microscope. At d10, mice were euthanized, the residualskin wound and underlying muscle tissue were dissected out, fixed inzinc-paraformaldehyde and prepared for embedding in paraffin or optimalcutting temperature (OCT) and sectioning.

Circular wound model: At day 0, 12-w-old athymic nude Foxn1 male mice(Harlan) were anesthetized with an i.p. injection of ketamine/xylazine.Atropine (0.01 mg/kg) was administered i.p. as premedication. Understerile and temperature-controlled (37° C.) conditions, standardizedfull-thickness wounds were made with a 0.5 cm biopsy puncher (StiefelLaboratories, Offenbach am Main, Germany) on the back of the mouse inthe mid-dorsal region. A silicone ring was fixed (using Histoacryltissue adhesive, Braun, Diegem, Belgium) and sutured around the woundand wounds were treated with saline or 5×10⁵ hMAPCs. In a separatesubset of mice, hMAPCs were transduced with an eGFP-encoding lentivirusbefore transplantation. An occlusive dressing (Tegaderm™, 3M, Diegem,Belgium) was used to keep the wound moist. All wounded mice were housedindividually to avoid fighting and to prevent removal of the occlusivewound dressing. Every other day, the occlusive dressing was renewedunder isoflurane anesthesia. At 5 d or 10 d after wounding, mice wereeuthanized and square skin fragments including the circular wound areaand a rim of normal skin were dissected out, rinsed in PBS andpost-fixed overnight at 4° C. using zinc-paraformaldehyde. Followingfixation, skin fragments were separated in two equal pieces at themidline of the wound and processed for paraffin or OCT embedding andsectioning.

Skin flap model: At day 0, 12-w-old athymic nude Foxn1 male mice(Harlan) were anesthetized with an i.p. injection of ketamine/xylazine.The lymphatic network in the abdominal skin was severed by elevating anepigastric skin flap and suturing it back to its original position, aspreviously described (Saaristo, A., et al. FASEB J (2004) 18:1707-1709).Continuous blood supply to the flap was insured by retaining a vascularpedicle including the right inferior epigastric artery and vein (FIG.3A). One day after resuturing the skin flap, 1×10⁶ mMAPCs, 1×10⁶ hMAPCsor PBS (divided over 4 injection spots; FIG. 3A) were injected aroundthe wound edges. Two or four weeks later, the axillary regions wereexposed and axillary lymph node drainage was monitored bymicrolymphangiography for 15 min after intradermal injection of 10 μlFITC-dextran (MW 2,000 kDa, Sigma-Aldrich; hMAPCs) or 10 μlRhodamin-B-isothiocyanate-dextran (MW 70 kDa, Sigma-Aldrich; mMAPCs)under the wound border (FIG. 3A). Brightfield and fluorescence pictureswere taken at 15 min with a Zeiss MRc5 camera mounted onto a Zeiss Lumarmicroscope. Mice were subsequently euthanized, the skin wound areaaround the cell engraftment/microlymphangiography areas excised, fixedand processed for paraffin or OCT embedding and sectioning.

Lymph node transplantation model: At day 0, 12-w-old athymic nude Foxn1female recipient mice (Harlan) were anesthetized with an i.p. injectionof ketamine (100 mg/kg) and xylazine (10 mg/kg). To visualize the lymphnodes, the right axilla region was exposed and mice were injected with a3% Evans Blue solution in the palm of the right paw after which lymphnodes were removed along with the surrounding lymphatic (collector)vessels. A pocket just caudal of the axillary vessels, aligned by thelateral axillary fat pad, the M. pectoralis and the M. latissimus dorsiwas prepared. Donor lymph nodes were dissected from mice ubiquitouslyexpressing DsRed (B6.Cg-Tg(CAG-DsRed*MST)1Nagy/J; for mice receivinghMAPCs or PBS and followed up for 4 w or 8 w) or enhanced (e)GFP(C57BL/6-Tg(CAG-EGFP)1Osb/J; for mice receiving hMAPCs or PBS andfollowed up for 4 w or 16 w) and cut in two halves through the hilus.The cut lymph node was subsequently implanted into the recipient pocket(hilus oriented medially and cut surface facing upwards) and fixed inplace with two permanent sutures (using 9-0 nylon non-absorbable suture,Monosof™). Cold growth factor-reduced Matrigel® (100 μl; BecktonDickinson) mixed with 0.5×10⁶ hMAPCs or PBS was applied into the pocketand allowed to solidify for 10 min. The skin was subsequently closed andthe wound covered with Tegaderm™ dressing. Four, eight or sixteen weekslater, mice were anesthetized with a ketamine/xylazine mixture andsubjected to microlymphangiography following injection of 10 μlFITC-conjugated L. esculentum lectin (Vector Laboratories; in recipientsof DsRed⁺ donor lymph nodes) or 10 μl Texas Red-conjugated L. esculentumlectin (in recipients of eGFP⁺ lymph nodes) in the palm of the rightpaw. Drainage of the implanted lymph node was monitored for 15 min andbrightfield and fluorescence pictures were taken at the end with a ZeissMRc5 camera mounted onto a Zeiss Lumar microscope. Mice weresubsequently euthanized, the axilla regions containing the transplantedlymph node excised, fixed and processed for paraffin or OCT embeddingand sectioning. Two additional sets of mice were subjected to in vivomagnetic resonance imaging (MRI; as described (Tammela, T., et al. NatMed (2007) 13:1458-1466) at 4 w or 16 w after lymph nodetransplantation. Briefly, mice were anesthetized with isoflurane andmustard oil (diluted 1/5 in mineral oil) was applied with a cotton stickon both fore limbs for 2×15 min to elicit vascular hyperpermeability andaggravate edema. Mice were allowed to recover for another 30 min beforeMRI recording. Temperature and respiration were monitored throughout theexperiment and maintained at 37° C. and 100-120 breaths per min. MRimages were acquired with a 9.4T Biospec small animal MR scanner (BrukerBiospin, Ettlingen, Germany) equipped with a horizontal bore magnet andan actively shielded gradient set of 600 mT per m (117 mm innerdiameter) using a 7 cm linearly polarized resonator for transmission andan actively decoupled dedicated 2 cm diameter surface coil for receiving(Rapid Biomedical, Rimpar, Germany) After the acquisition of 2Dlocalization scans; 3D T₂ weighted images, 2D T₂ parameter maps and 2Ddiffusion weighted images were acquired to determine the level of edema.Specific parameters were: 3D rapid acquisition with refocused echoes(RARE) sequence, repetition time (TR): 1300 ms, effective echo time(TE): 22.9 ms, rare factor: 6, matrix size: 256×48×48, field of view(FOV): 2.5×0.7×1.5 cm, resolution: 98×146×312 μm³; 2D T₂ maps: TR: 3500ms, 10 TE's between: 10-100 ms, matrix size: 256×256, FOV: 2×2 cm, 15transverse slices with slice thickness: 0.3 mm and gap 0.3 mm, in planeresolution: 78 μm²; diffusion weighted MRI: spin echo sequence; b-valueof 1500 s mm², TR: 25 ms, TE: 3,000 ms, matrix size: 128×128, FOV: 2×2cm, 8 transverse slices of 1 mm thickness. Processing of the 3D T₂weighted images was done by determining the volume with a signalintensity above a common threshold value using home-written softwaredeveloped with Mevislab (Mevis Medical Solutions, Bremen, Germany)reported as ratio's between the lymph node implanted site versus thecontrol site. Calculation of the T₂ parameter maps of the manuallydelineated edema of the paws (or an area of the same size and located inthe same region in the absence of edema) was done using Paravison 5.1(Bruker Biospin).

Histology and Morphometry

Morphometric analyses were performed on 7 μm paraffin sections, 10 μmcryosections or brightfield pictures of exposed skin regions by blindedobservers. Lymphatic (determined on LYVE1-, Flt4- or Prox1/αSMA-stainedsections) or blood (determined on CD31-stained sections) vessel densityand epithelial coverage (determined on pancytokeratin-stained sections)was scored on at least 10 randomly chosen fields per mouse, covering adistance of 700 μm. Functional lymphatics (determined on cryosections ofmice injected with fluorescently-labeled dextran) were counted on 8-10consecutive sections per mouse, thereby scanning the entire wound areavisible on each section. The fractional area of the blood vessel networkleading up to the transplanted lymph nodes was determined on digitallyreconstructed images of the entire region of interest. For stainings onparaffin sections, slides were deparaffinated and rehydrated,cryosections were incubated in PBS for five min prior to the stainingprocedure. H&E staining was performed as previously described (1). ForCD31, Flt4 or pancytokeratin immunohistochemical staining, antigenretrieval was performed by boiling in target retrieval solution s1699(Sigma). After cooling down in TBS, endogenous peroxidase activity wasquenched in 0.3% H₂O₂ in methanol. Slides were incubated with primary Abovernight. A list of primary Ab's is provided in Table 4. After washingin TBS, slides were incubated for 2 h with biotinylated rabbit-anti-rat(CD31 and Flt4) or goat anti-mouse (pancytokeratin) Ab's and thedetection signal was amplified with a tyramide signal amplificationsystem (Perkin Elmer, NEL700A). Nuclei were revealed by hematoxylincounterstaining and slides were mounted with DPX mountant (Sigma). ForLYVE1 immunofluorescence (IF) staining, antigen retrieval was performedby boiling in target retrieval solution s1699 (Sigma). After coolingdown in TBS, endogenous peroxidase activity was quenched in 0.3% H₂O₂ inmethanol. Slides were incubated with primary Ab overnight. After washingin TBS, slides were incubated for 2 h with biotinylated goat-anti-rabbitAb and the detection signal was amplified with a tyramide-Cy3 ortyramide-fluorescein signal amplification system (Perkin Elmer, NEL704Aor NEL701A). When combined with CD45 IF staining, slides weresubsequently incubated with primary anti-CD45 Ab overnight, followed bya 2 h incubation with goat-anti-rat-Alexa488. For GFP or vimentin IFstaining, antigen retrieval was performed by boiling in citrate buffer(pH=6). After overnight incubation with primary Ab, slides wereincubated for 1 h with Alexa-conjugated donkey-anti-chicken (GFP) orgoat-anti-mouse (vimentin) Ab's. For combined LYVE1/vimentin IFstaining, antigen retrieval was performed by boiling in citrate buffer(pH=6) and tissues were permeabilized by incubation in Triton 0.1% inPBS. After overnight incubation with primary Abs, slides were incubatedfor 1 h with goat-anti-mouse-Alexa488 and goat-anti-rabbit-Alexa568. Forcombined Prox1/αSMA IF staining, antigen retrieval was performed byboiling in citrate buffer (pH=6) and tissues were permeabilized byincubation in Triton 0.1% in PBS. After overnight incubation with Prox1primary Ab, slides were incubated for 1 h with biotin-conjugatedgoat-anti-rabbit Ab and the detection signal was amplified with atyramide-Cy3 or tyramide-fluorescein signal amplification system (PerkinElmer, NEL704A or NEL701A). Slides were subsequently stained withCy3-conjugated αSMA for 2 h or with unconjugated SMA followed bygoat-anti-mouse-Alexa660. For combined Prox1/eGFP IF staining, antigenretrieval was performed by boiling in citrate buffer (pH=6) and tissueswere permeabilized by incubation in Triton 0.1% in PBS. After overnightincubation with Prox1 and eGFP primary Ab's, slides were incubated for 1h with biotin-conjugated goat-anti-rabbit and Alexa488-conjugateddonkey-anti-chicken Ab's and the Prox1 detection signal was amplifiedwith a tyramide-Cy3 signal amplification system (Perkin Elmer).IF-stained slides were sealed with ProLong Gold Antifade Reagent withDAPI (Life Technologies; P36931) or without in case nuclei were revealedby Hoechst staining. All Images were recorded on a Zeiss Axiovert 200Mmicroscope, a Zeiss Axio Imager Z1 or a Zeiss LSM510 confocal microscopeequipped with a Zeiss MRc5 camera and Axiovision 4.8 software.

Statistics

n in results text and Figure/Table legends designates the number ofreplicates (i.e., each performed on different passages of a given MAPCclone; in vitro) or separate animals (in vivo). Normality of the datawas tested by the Shapiro-Wilk test. Comparisons among two groups wasperformed by Student's t-test in case of normal distribution or byMann-Whitney-U test in cases where data were not normally distributed ornormality could not be assumed. Multiple-group comparisons were done by1-way ANOVA with Tuckey's post-hoc test (normal distribution) orKruskal-Wallis test followed by Dunn's post-hoc test (no normalityassumption). Wound size was evaluated by repeated measures ANOVA,followed by Fisher least-significant-difference test. All analyses wereperformed with Graphpad Prism (version 6.0).

Tables

TABLE 1 Lymphangiography in skin flap model PBS mMAPCs hMAPCs Day postoperation 14 28 14 28 14 Wound border crossing (%) 30.0 0.0 83.3 100.0100.0 Lymph node filling (%) 10.0 0.0 50.0  80.0 100.0Dextran⁺Prox1⁺αSMA⁺ 3 ± 1 ND ND ND 10 ± 3^(A) (pre-) collectors (averagenumber per cross-section) Data represent fraction of mice revealing thefunctional feature mentioned in the left column or the mean ± SEM. (PBS:n = 10 for each time point; mMAPCs: n = 6 for 14 d and n = 5 for 28 d;hMAPCs: n = 6). ND, not determined. ^(A)P < 0.05 versus PBS by unpairedStudent's t-test.

TABLE 2 Lymphangiography in LN transplantation model PBS hMAPC1 hMAPC2Week 4 8 16 4 8 16 4 8 16 Survival (%) 100.0  83.0  50.0  100.0 100.0100.0 100.0 100.0 100.0 Size (mm²) 0.74 ± 0.20 0.25 ± 0.10 0.35 ± 0.240.64 ± 0.13 1.20 ± 0.18^(A) 1.08 ± 0.12^(A) ND ND ND Branching (%) 0.00.0 0.0 100.0 100.0 100.0 100.0 100.0 100.0 Filling (%) 0.0 0.0 0.0  0.0 33.3  62.5  0.0  37.5  50.0 Data represent fraction of mice revealingthe functional feature of the transplanted LN mentioned in the leftcolumn or mean ± SEM. (PBS: n = 10, 6 and 6 for 4 w, 8 w and 16 w,respectively; hMAPC1: n = 10, 6 and 8 for 4 w, 8 w and 16 w,respectively; hMAPC2: n = 6, 8 and 4 for 4 w, 8 w and 16 w,respectively); ND: not determined. ^(A)P < 0.05 versus corresponding PBScondition by Mann-Whitney-U test.

TABLE 3 qRT-PCR primers 5′-3′ SEQ 5′-3′ SEQ forward ID reverse ID Geneprimer NO: primer NO: Prox1 (M) CGCGT 1 GGGCT 2 GGGTT GTGCT TCTTC GTCATTCTGC GGTCA Pdpn (M) GCCAG 3 AGAGG 4 TGTTG TGCCT TTCTG TGCCA GGTTT GTAGAItga9 (M) CTGCT 5 AATGC 6 TTCCA CCATC GTGTT TCCTC GACGA CTTCT Flt1 (M)TGGCC 7 TCGCA 8 AGAGG AATCT CATGG TCACC AGT ACATG G Tek1 (M) GAAAC 9TGGCC 10 ATCCC TTTTC TCACC TCTCT TGCAT TCCAA VWF (M) AAGGA 11 GCGTG 12GCAGG TATGT ACCTG GAGGA GAAGT TGTGG Gapdh (M) CCGCA 13 GAATT 14 TCTTCTGCCG TTGTG TGAGT CAGT GGAGT PROX1 (H) CAGTA 15 TCTGA 16 CTGAA GCAACGAGCT TTCCA GTCTA GGAAT TAACC CTC AGAG PDPN (H) TGCTC 17 TCGCT 18 TTCGTGGTTC TTTGG CTGGA GAAGC GTCAC ITGA9 (H) AGGAC 19 GCACT 20 GCTGA TTGATTCCCT GGTTC TGCTA CAGCC FLT1 (H) TTTGG 21 CGGCA 22 ATGAG CGTAG CAGTGGTGAT TGAGC TTCTT TEK1 (H) ACACC 23 AGCAG 24 TGCCT TACAG CATGC AGATGTCAGC GTTGC ATTC VWF (H) TGCTG 25 CCGGA 26 GTATG ATGCA GAGTA CGCAG TAGGCG AGTG GAPDH (H) TGGTA 27 ATGCC 28 TCGTG AGTGA GAAGG GCTTC ACTCA CCGTTTGAC CAGC

TABLE 4 List of antibodies for histology Antigen Target speciesSupplier, catalog No CD31 mouse Beckton Dickinson, 557355 LYVE1 mouse +human Upstate Biotechnology, 07-538 Pancytokeratin mouse Sigma, C-2562(PCK) Flt4 mouse eBioscience, 14-5988-82 Smooth muscle mouse + humanSigma C-6148 or A5228 α-actin (SMA) CD45 mouse Beckton Dickinson, 553076Prox1 mouse + human Angiobio, 11-002 Vimentin human DAKO, Clone V9 eGFPchicken Abcam, ab13970

What is claimed is:
 1. A method to promote cutaneous burn healing in a subject by administering cells (I) in an effective amount and for a time sufficient to promote the cutaneous burn healing, wherein the cells (I) are not delivered from a functionalized substrate, wherein the cells (I) are non-embryonic non-germ cells that express CD90 and oct4 or telomerase, are not transformed, are not tumorigenic, and have a normal karyotype.
 2. The method of claim 1, wherein the cells (I) express telomerase.
 3. The method of either of claim 1 or 2, wherein the cells (I) can differentiate into at least one cell type of at least two of the endodermal, ectodermal, and mesodermal embryonic lineages.
 4. The method of claim 3, wherein the cells (I) can differentiate into at least one cell type of each of the endodermal, ectodermal, and mesodermal embryonic lineages.
 5. The method of claim 1, wherein the burn is of the skin and underlying tissues. 6-8. (canceled)
 9. The method of either of claim 1 or 2, wherein the cells (I) are not genetically manipulated.
 10. The method of either of claim 1 or 2, wherein the cells (I) are derived from bone marrow.
 11. The method of either of claim 1 or 2, wherein the cells (I) are derived from a human.
 12. The method of either of claim 1 or 2, wherein the subject is human.
 13. (canceled)
 14. The method of either of claim 1 or 2, wherein the cells (I) are administered to the burn topically.
 15. The method of either of claim 1 or 2, wherein the cells (I) are delivered subcutaneously.
 16. The method of either of claim 1 or 2, wherein the cells (I) are administered to the burn by injection.
 17. The method of either of claim 1 or 2, wherein the cells (I) are administered in liquid cell suspension.
 18. The method of either of claim 1 or 2, wherein the cells (I) are administered to the burn using a reservoir.
 19. The method of either of claim 1 or 2, wherein the cells (I) are allogeneic. 